Use dense, per mailbox UIDs.denseuid

Signed-off-by: James Cloos <cloos@jhcloos.com>

22 files changed, 233 insertions, 137 deletions

diff --git a/check_dbmail_misc.c b/check_dbmail_misc.c
index 6d5f4b63..61400655 100644
--- a/check_dbmail_misc.c
+++ b/check_dbmail_misc.c
@@ -246,8 +246,8 @@ START_TEST(test_create_unique_id)
 {
 	char *a = g_new0(char, 64);
 	char *b = g_new0(char, 64);
-	create_unique_id(a,0);
-	create_unique_id(b,0);
+	create_unique_id(a,0,0);
+	create_unique_id(b,0,0);
 	fail_unless(strlen(a)==32, "create_unique_id produced incorrect string length [%s]", a);
 	fail_unless(strlen(b)==32, "create_unique_id produced incorrect string length [%s]", b);
 	fail_unless(!MATCH(a,b),"create_unique_id shouldn't produce identical output");
diff --git a/db.c b/db.c
index 746ad3e8..5730e2df 100644
--- a/db.c
+++ b/db.c
@@ -325,7 +325,7 @@ int db_rollback_savepoint_transaction(const char* name)
 	return DM_SUCCESS;
 }
 
-int db_get_physmessage_id(u64_t message_idnr, u64_t * physmessage_id)
+int db_get_physmessage_id(u64_t mailbox_idnr, u64_t message_idnr, u64_t * physmessage_id)
 {
 	char query[DEF_QUERYSIZE]; 
 	memset(query,0,DEF_QUERYSIZE);
@@ -335,7 +335,7 @@ int db_get_physmessage_id(u64_t message_idnr, u64_t * physmessage_id)
 
 	snprintf(query, DEF_QUERYSIZE,
 		 "SELECT physmessage_id FROM %smessages "
-		 "WHERE message_idnr = %" U64_T_FORMAT, DBPFX, message_idnr);
+		 "WHERE mailbox_idnr = %" U64_T_FORMAT " AND message_idnr = %" U64_T_FORMAT, DBPFX, mailbox_idnr, message_idnr);
 
 	if (db_query(query) == -1) {
 		TRACE(TRACE_ERROR, "error getting physmessage_id");
@@ -1060,6 +1060,7 @@ int db_get_reply_body(u64_t user_idnr, char **reply_body)
 	return DM_SUCCESS;
 }
 
+/* Cannot really have this w/ per-mailbox uids.... */
 u64_t db_get_mailbox_from_message(u64_t message_idnr)
 {
 	u64_t mailbox_idnr;
@@ -1087,7 +1088,7 @@ u64_t db_get_mailbox_from_message(u64_t message_idnr)
 	return mailbox_idnr;
 }
 
-u64_t db_get_useridnr(u64_t message_idnr)
+u64_t db_get_useridnr(u64_t mailbox_idnr, u64_t message_idnr)
 {
 	const char *query_result;
 	u64_t user_idnr;
@@ -1098,8 +1099,9 @@ u64_t db_get_useridnr(u64_t message_idnr)
 	snprintf(query, DEF_QUERYSIZE,
 		 "SELECT %smailboxes.owner_idnr FROM %smailboxes, %smessages "
 		 "WHERE %smailboxes.mailbox_idnr = %smessages.mailbox_idnr "
+		 "AND %smessages.mailbox_idnr = %" U64_T_FORMAT " "
 		 "AND %smessages.message_idnr = %" U64_T_FORMAT, DBPFX,DBPFX,DBPFX,
-		DBPFX,DBPFX,DBPFX,message_idnr);
+		 DBPFX,DBPFX,DBPFX,mailbox_idnr,DBPFX,message_idnr);
 	if (db_query(query) == -1) {
 		/* query failed */
 		TRACE(TRACE_ERROR, "query failed" );
@@ -1133,12 +1135,14 @@ int db_insert_physmessage_with_internal_date(timestring_t internal_date,
 		to_date_str = char2date_str(internal_date);
 		snprintf(query, DEF_QUERYSIZE,
 			 "INSERT INTO %sphysmessage (messagesize, internal_date) "
-			 "VALUES (0, %s)", DBPFX,to_date_str);
+			 "VALUES (0, %s) %s", DBPFX,to_date_str,
+			 db_returning("id"));
 		g_free(to_date_str);
 	} else {
 		snprintf(query, DEF_QUERYSIZE,
 			 "INSERT INTO %sphysmessage (messagesize, internal_date) "
-			 "VALUES (0, %s)", DBPFX,db_get_sql(SQL_CURRENT_TIMESTAMP));
+			 "VALUES (0, %s) %s", DBPFX,db_get_sql(SQL_CURRENT_TIMESTAMP),
+			 db_returning("id"));
 	}
 	
 	if (db_query(query) == -1) {
@@ -1155,7 +1159,7 @@ int db_insert_physmessage(u64_t * physmessage_id)
 	return db_insert_physmessage_with_internal_date(NULL, physmessage_id);
 }
 
-int db_message_set_unique_id(u64_t message_idnr, const char *unique_id)
+int db_message_set_unique_id(u64_t mailbox_idnr, u64_t message_idnr, const char *unique_id)
 {
 	char query[DEF_QUERYSIZE]; 
 	memset(query,0,DEF_QUERYSIZE);
@@ -1164,11 +1168,11 @@ int db_message_set_unique_id(u64_t message_idnr, const char *unique_id)
 	
 	snprintf(query, DEF_QUERYSIZE,
 		 "UPDATE %smessages SET unique_id = '%s', status = %d "
-		 "WHERE message_idnr = %" U64_T_FORMAT, DBPFX, unique_id, MESSAGE_STATUS_NEW,
-		 message_idnr);
+		 "WHERE mailbox_idnr = %" U64_T_FORMAT " AND message_idnr = %" U64_T_FORMAT, DBPFX,
+		 unique_id, MESSAGE_STATUS_NEW, mailbox_idnr, message_idnr);
 	if (db_query(query) == DM_EQUERY) {
-		TRACE(TRACE_ERROR, "setting unique id for message [%" U64_T_FORMAT "] failed",
-		      message_idnr);
+		TRACE(TRACE_ERROR, "setting unique id for mailbox [%" U64_T_FORMAT "] message [%" U64_T_FORMAT "] failed",
+		      mailbox_idnr, message_idnr);
 		return DM_EQUERY;
 	}
 	return DM_SUCCESS;
@@ -1194,27 +1198,27 @@ int db_physmessage_set_sizes(u64_t physmessage_id, u64_t message_size,
 	return DM_SUCCESS;
 }
 
-int db_update_message(u64_t message_idnr, const char *unique_id,
+int db_update_message(u64_t mailbox_idnr, u64_t message_idnr, const char *unique_id,
 		      u64_t message_size, u64_t rfc_size)
 {
 	assert(unique_id);
 	u64_t physmessage_id = 0;
 
-	if (db_message_set_unique_id(message_idnr, unique_id))
+	if (db_message_set_unique_id(mailbox_idnr, message_idnr, unique_id))
 		return DM_EQUERY;
 
 	/* update the fields in the physmessage table */
-	if (db_get_physmessage_id(message_idnr, &physmessage_id)) 
+	if (db_get_physmessage_id(mailbox_idnr, message_idnr, &physmessage_id)) 
 		return DM_EQUERY;
 
 	if (db_physmessage_set_sizes(physmessage_id, message_size, rfc_size)) 
 		return DM_EQUERY;
 
-	if (user_quotum_inc(db_get_useridnr(message_idnr), message_size)) {
+	if (user_quotum_inc(db_get_useridnr(mailbox_idnr, message_idnr), message_size)) {
 		TRACE(TRACE_ERROR, "error calculating quotum "
 		      "used for user [%" U64_T_FORMAT "]. Database might be "
 		      "inconsistent. Run dbmail-util.",
-		      db_get_useridnr(message_idnr));
+		      db_get_useridnr(mailbox_idnr, message_idnr));
 		return DM_EQUERY;
 	}
 	return DM_SUCCESS;
@@ -1255,8 +1259,8 @@ int db_insert_message_block_physmessage(const char *block,
 	/* escape & add data */
 	esclen = db_escape_binary(&escaped_query[startlen], block, block_size);
 	snprintf(&escaped_query[esclen + startlen],
-		 maxesclen - esclen - startlen, "', %" U64_T_FORMAT ", %" U64_T_FORMAT ")",
-		 block_size, physmessage_id);
+		 maxesclen - esclen - startlen, "', %" U64_T_FORMAT ", %" U64_T_FORMAT ") %s",
+		 block_size, physmessage_id, db_returning("messageblk_idnr"));
 
 	if (db_query(escaped_query) == DM_EQUERY) {
 		g_free(escaped_query);
@@ -1271,7 +1275,7 @@ int db_insert_message_block_physmessage(const char *block,
 }
 
 int db_insert_message_block(const char *block, u64_t block_size,
-			    u64_t message_idnr, u64_t *physmessage_id, u64_t * messageblk_idnr, unsigned is_header)
+			    u64_t mailbox_idnr, u64_t message_idnr, u64_t *physmessage_id, u64_t * messageblk_idnr, unsigned is_header)
 {
 	assert(messageblk_idnr != NULL);
 	*messageblk_idnr = 0;
@@ -1280,7 +1284,7 @@ int db_insert_message_block(const char *block, u64_t block_size,
 		return DM_EQUERY;
 	}
 
-	if ((! *physmessage_id) && (db_get_physmessage_id(message_idnr, physmessage_id) == DM_EQUERY)) {
+	if ((! *physmessage_id) && (db_get_physmessage_id(mailbox_idnr, message_idnr, physmessage_id) == DM_EQUERY)) {
 		TRACE(TRACE_ERROR, "error getting physmessage_id");
 		return DM_EQUERY;
 	}
@@ -1600,7 +1604,7 @@ int db_icheck_physmessages(gboolean cleanup)
 
 int db_icheck_messages(struct dm_list *lost_list)
 {
-	u64_t message_idnr;
+	static box_uid_t box_uid = { .mailbox = 0, .uid = 0 };
 	int i, n;
 	char query[DEF_QUERYSIZE]; 
 	memset(query,0,DEF_QUERYSIZE);
@@ -1609,7 +1613,7 @@ int db_icheck_messages(struct dm_list *lost_list)
 	dm_list_init(lost_list);
 
 	snprintf(query, DEF_QUERYSIZE,
-		 "SELECT msg.message_idnr FROM %smessages msg "
+		 "SELECT msg.mailbox_idnr, msg.message_idnr FROM %smessages msg "
 		 "LEFT JOIN %smailboxes mbx ON "
 		 "msg.mailbox_idnr=mbx.mailbox_idnr "
 		 "WHERE mbx.mailbox_idnr IS NULL",DBPFX,DBPFX);
@@ -1627,11 +1631,14 @@ int db_icheck_messages(struct dm_list *lost_list)
 	}
 
 	for (i = 0; i < n; i++) {
-		if (!(message_idnr = db_get_result_u64(i, 0)))
+		if (!(box_uid.mailbox = db_get_result_u64(i, 0)))
 			continue;
 
-		TRACE(TRACE_INFO, "found lost message id [%" U64_T_FORMAT "]", message_idnr);
-		if (!dm_list_nodeadd(lost_list, &message_idnr, sizeof(u64_t))) {
+		if (!(box_uid.uid = db_get_result_u64(i, 1)))
+			continue;
+
+		TRACE(TRACE_INFO, "found lost message id [%" U64_T_FORMAT "/%" U64_T_FORMAT "]", box_uid.mailbox, box_uid.uid);
+		if (!dm_list_nodeadd(lost_list, &box_uid, sizeof(box_uid_t))) {
 			TRACE(TRACE_ERROR, "could not add message to list");
 			dm_list_free(&lost_list->start);
 			db_free_result();
@@ -1734,7 +1741,7 @@ int db_icheck_null_physmessages(struct dm_list *lost_list)
 
 int db_icheck_null_messages(struct dm_list *lost_list)
 {
-	u64_t message_idnr;
+	static box_uid_t box_uid = { .mailbox = 0, .uid = 0 };
 	int i, n;
 	char query[DEF_QUERYSIZE]; 
 	memset(query,0,DEF_QUERYSIZE);
@@ -1743,7 +1750,7 @@ int db_icheck_null_messages(struct dm_list *lost_list)
 	dm_list_init(lost_list);
 
 	snprintf(query, DEF_QUERYSIZE,
-		 "SELECT msg.message_idnr FROM %smessages msg "
+		 "SELECT msg.mailbox_idnr, msg.message_idnr FROM %smessages msg "
 		 "LEFT JOIN %sphysmessage pm ON "
 		 "msg.physmessage_id = pm.id WHERE pm.id is NULL",DBPFX,DBPFX);
 
@@ -1760,11 +1767,14 @@ int db_icheck_null_messages(struct dm_list *lost_list)
 	}
 
 	for (i = 0; i < n; i++) {
-		if (!(message_idnr = db_get_result_u64(i, 0)))
+		if (!(box_uid.mailbox = db_get_result_u64(i, 0)))
+			continue;
+
+		if (!(box_uid.uid = db_get_result_u64(i, 1)))
 			continue;
 
-		TRACE(TRACE_INFO, "found empty message id [%" U64_T_FORMAT "]", message_idnr);
-		if (!dm_list_nodeadd(lost_list, &message_idnr, sizeof(u64_t))) {
+		TRACE(TRACE_INFO, "found empty mailbox id [ %" U64_T_FORMAT "] message id [%" U64_T_FORMAT "]", box_uid.mailbox, box_uid.uid);
+		if (!dm_list_nodeadd(lost_list, &box_uid, sizeof(box_uid_t))) {
 			TRACE(TRACE_ERROR, "could not add message to list");
 			dm_list_free(&lost_list->start);
 			db_free_result();
@@ -2046,13 +2056,13 @@ int db_icheck_envelope(GList **lost)
 }
 
 
-int db_set_message_status(u64_t message_idnr, MessageStatus_t status)
+int db_set_message_status(u64_t mailbox_idnr, u64_t message_idnr, MessageStatus_t status)
 {
 	char query[DEF_QUERYSIZE]; 
 	memset(query,0,DEF_QUERYSIZE);
 
-	snprintf(query, DEF_QUERYSIZE, "UPDATE %smessages SET status = %d WHERE message_idnr = %" U64_T_FORMAT,
-		DBPFX, status, message_idnr);
+	snprintf(query, DEF_QUERYSIZE, "UPDATE %smessages SET status = %d WHERE mailbox_idnr = %" U64_T_FORMAT " AND message_idnr = %" U64_T_FORMAT,
+		DBPFX, status, mailbox_idnr, message_idnr);
 	return db_query(query);
 }
 
@@ -2092,7 +2102,7 @@ int db_delete_physmessage(u64_t physmessage_id)
 	return DM_EGENERAL;
 }
 
-int db_delete_message(u64_t message_idnr)
+int db_delete_message(u64_t mailbox_idnr, u64_t message_idnr)
 {
 	u64_t physmessage_id;
 	int rows;
@@ -2100,25 +2110,25 @@ int db_delete_message(u64_t message_idnr)
 	memset(query,0,DEF_QUERYSIZE);
 
 
-	if (db_get_physmessage_id(message_idnr, &physmessage_id) == DM_EQUERY)
+	if (db_get_physmessage_id(mailbox_idnr, message_idnr, &physmessage_id) == DM_EQUERY)
 		return DM_EQUERY;
 
 	/* now delete the message from the message table */
 	snprintf(query, DEF_QUERYSIZE, "DELETE FROM %smessages "
-			"WHERE message_idnr = %" U64_T_FORMAT,
-			DBPFX, message_idnr);
+			"WHERE mailbox_idnr = %" U64_T_FORMAT " AND message_idnr = %" U64_T_FORMAT,
+			DBPFX, mailbox_idnr, message_idnr);
 	
 	if (db_query(query) == DM_EQUERY) {
-		TRACE(TRACE_ERROR,"error deleting message [%" U64_T_FORMAT "]", message_idnr);
+		TRACE(TRACE_ERROR,"error deleting mailbox [%" U64_T_FORMAT "] message [%" U64_T_FORMAT "]", mailbox_idnr, message_idnr);
 		return DM_EQUERY;
 	}
 
 	/* find other messages pointing to the same physmessage entry */
-	snprintf(query, DEF_QUERYSIZE, "SELECT message_idnr FROM %smessages "
+	snprintf(query, DEF_QUERYSIZE, "SELECT mailbox_idnr, message_idnr FROM %smessages "
 			"WHERE physmessage_id = %" U64_T_FORMAT,DBPFX, physmessage_id);
 	
 	if (db_query(query) == -1) {
-		TRACE(TRACE_ERROR, "error finding physmessage for message [%" U64_T_FORMAT "]", message_idnr);
+		TRACE(TRACE_ERROR, "error finding physmessage for mailbox [%" U64_T_FORMAT "] message [%" U64_T_FORMAT "]", mailbox_idnr, message_idnr);
 		return DM_EQUERY;
 	}
 	
@@ -2183,7 +2193,7 @@ static int mailbox_empty(u64_t mailbox_idnr)
 	db_free_result();
 	/* delete every message in the mailbox */
 	for (i = 0; i < n; i++) {
-		if (db_delete_message(message_idnrs[i]) == -1) {
+		if (db_delete_message(mailbox_idnr, message_idnrs[i]) == -1) {
 			g_free(message_idnrs);
 			return DM_EQUERY;
 		}
@@ -2243,7 +2253,7 @@ int db_delete_mailbox(u64_t mailbox_idnr, int only_empty,
 	return DM_SUCCESS;
 }
 
-int db_send_message_lines(void *fstream, u64_t message_idnr, long lines, int no_end_dot)
+int db_send_message_lines(void *fstream, u64_t mailbox_idnr, u64_t message_idnr, long lines, int no_end_dot)
 {
 	struct DbmailMessage *msg;
 	
@@ -2256,7 +2266,7 @@ int db_send_message_lines(void *fstream, u64_t message_idnr, long lines, int no_
 	TRACE(TRACE_DEBUG, "request for [%ld] lines", lines);
 
 	/* first find the physmessage_id */
-	if (db_get_physmessage_id(message_idnr, &physmessage_id) != DM_SUCCESS)
+	if (db_get_physmessage_id(mailbox_idnr, message_idnr, &physmessage_id) != DM_SUCCESS)
 		return DM_EGENERAL;
 
 	TRACE(TRACE_DEBUG, "sending [%ld] lines from message [%" U64_T_FORMAT "]",
@@ -2320,6 +2330,8 @@ int db_createsession(u64_t user_idnr, PopSession_t * session_ptr)
 
 	g_return_val_if_fail(mailbox_idnr > 0, DM_EQUERY);
 
+	session_ptr->mailbox_idnr = mailbox_idnr;
+
 	/* query is < MESSAGE_STATUS_DELETE  because we don't want deleted 
 	 * messages
 	 */
@@ -2420,14 +2432,19 @@ int db_update_pop(PopSession_t * session_ptr)
 				user_idnr =
 				    db_get_useridnr(((struct message *)
 						     tmpelement->data)->
+						    mailbox,
+						    ((struct message *)
+						     tmpelement->data)->
 						    realmessageid);
 
 			/* yes they need an update, do the query */
 			snprintf(query, DEF_QUERYSIZE,
 				 "UPDATE %smessages set status=%d WHERE "
-				 "message_idnr=%" U64_T_FORMAT " AND status < %d",DBPFX,
+				 "mailbox_idnr=%" U64_T_FORMAT " AND message_idnr=%" U64_T_FORMAT " AND status < %d",DBPFX,
 				 ((struct message *)
 				  tmpelement->data)->virtual_messagestatus,
+				 ((struct message *)
+				  tmpelement->data)->mailbox,
 				 ((struct message *) tmpelement->data)->
 				 realmessageid, MESSAGE_STATUS_DELETE);
 
@@ -2497,6 +2514,7 @@ int db_deleted_purge(u64_t * affected_rows)
 	char query[DEF_QUERYSIZE]; 
 	memset(query,0,DEF_QUERYSIZE);
 
+	u64_t *mailbox_idnrs;
 	u64_t *message_idnrs;
 
 	assert(affected_rows != NULL);
@@ -2504,12 +2522,12 @@ int db_deleted_purge(u64_t * affected_rows)
 
 	/* first we're deleting all the messageblks */
 	snprintf(query, DEF_QUERYSIZE,
-		 "SELECT message_idnr FROM %smessages WHERE status=%d",DBPFX,
+		 "SELECT mailbox_idnr, message_idnr FROM %smessages WHERE status=%d",DBPFX,
 		 MESSAGE_STATUS_PURGE);
 	TRACE(TRACE_DEBUG, "executing query [%s]", query);
 
 	if (db_query(query) == -1) {
-		TRACE(TRACE_ERROR, "Cound not fetch message ID numbers");
+		TRACE(TRACE_ERROR, "Cound not fetch mailbox/message ID number tuples");
 		return DM_EQUERY;
 	}
 
@@ -2520,21 +2538,26 @@ int db_deleted_purge(u64_t * affected_rows)
 		return DM_SUCCESS;
 	}
 
+	mailbox_idnrs = g_new0(u64_t, *affected_rows);
 	message_idnrs = g_new0(u64_t, *affected_rows);
 	
 	/* delete each message */
-	for (i = 0; i < *affected_rows; i++)
-		message_idnrs[i] = db_get_result_u64(i, 0);
-	
+	for (i = 0; i < *affected_rows; i++) {
+		mailbox_idnrs[i] = db_get_result_u64(i, 0);
+		message_idnrs[i] = db_get_result_u64(i, 1);
+	}
+
 	db_free_result();
 	for (i = 0; i < *affected_rows; i++) {
-		if (db_delete_message(message_idnrs[i]) == -1) {
-			TRACE(TRACE_ERROR, "error deleting message");
+	    if (db_delete_message(mailbox_idnrs[i], message_idnrs[i]) == -1) {
+			TRACE(TRACE_ERROR, "error deleting mailbox [%" U64_T_FORMAT "] message [%" U64_T_FORMAT "]",
+				mailbox_idnrs[i], message_idnrs[i]);
 			g_free(message_idnrs);
 			return DM_EQUERY;
 		}
 	}
 	g_free(message_idnrs);
+	g_free(mailbox_idnrs);
 	
 	return DM_EGENERAL;
 }
@@ -2593,8 +2616,8 @@ int db_imap_append_msg(const char *msgdata, u64_t datalen UNUSED,
 	}
 
         dbmail_message_store(message);
-	result = db_copymsg(message->id, mailbox_idnr, user_idnr, msg_idnr);
-	db_delete_message(message->id);
+	result = db_copymsg(message->mailbox, message->id, mailbox_idnr, user_idnr, msg_idnr);
+	db_delete_message(mailbox_idnr, message->id);
         dbmail_message_free(message);
 	
         switch (result) {
@@ -2615,7 +2638,7 @@ int db_imap_append_msg(const char *msgdata, u64_t datalen UNUSED,
 	
         TRACE(TRACE_MESSAGE, "message id=%" U64_T_FORMAT " is inserted", *msg_idnr);
         
-        return db_set_message_status(*msg_idnr, MESSAGE_STATUS_SEEN);
+        return db_set_message_status(mailbox_idnr, *msg_idnr, MESSAGE_STATUS_SEEN);
 }
 
 int db_findmailbox(const char *fq_name, u64_t owner_idnr, u64_t * mailbox_idnr)
@@ -3404,8 +3427,9 @@ int db_createmailbox(const char * name, u64_t owner_idnr, u64_t * mailbox_idnr)
 		 "INSERT INTO %smailboxes (name, owner_idnr,"
 		 "seen_flag, answered_flag, deleted_flag, flagged_flag, "
 		 "recent_flag, draft_flag, permission)"
-		 " VALUES ('%s', %" U64_T_FORMAT ", 1, 1, 1, 1, 1, 1, %d)",DBPFX,
-		 escaped_simple_name, owner_idnr, IMAPPERM_READWRITE);
+		 " VALUES ('%s', %" U64_T_FORMAT ", 1, 1, 1, 1, 1, 1, %d) %s",DBPFX,
+		 escaped_simple_name, owner_idnr, IMAPPERM_READWRITE,
+		 db_returning("mailbox_idnr"));
 
 	g_free(escaped_simple_name);
 
@@ -3801,7 +3825,7 @@ int db_mailbox_has_message_id(u64_t mailbox_idnr, const char *messageid)
 }
 
 
-static u64_t message_get_size(u64_t message_idnr)
+static u64_t message_get_size(u64_t mailbox_idnr, u64_t message_idnr)
 {
 	u64_t size = 0;
 	char query[DEF_QUERYSIZE]; 
@@ -3811,7 +3835,7 @@ static u64_t message_get_size(u64_t message_idnr)
 	snprintf(query, DEF_QUERYSIZE,
 		 "SELECT pm.messagesize FROM %sphysmessage pm, %smessages msg "
 		 "WHERE pm.id = msg.physmessage_id "
-		 "AND message_idnr = %" U64_T_FORMAT,DBPFX,DBPFX, message_idnr);
+		 "AND mailbox_idnr = %" U64_T_FORMAT " AND message_idnr = %" U64_T_FORMAT,DBPFX,DBPFX, mailbox_idnr, message_idnr);
 
 	if (db_query(query))
 		return size; /* err */
@@ -3823,8 +3847,8 @@ static u64_t message_get_size(u64_t message_idnr)
 	return size;
 }
 
-int db_copymsg(u64_t msg_idnr, u64_t mailbox_to, u64_t user_idnr,
-	       u64_t * newmsg_idnr)
+int db_copymsg(u64_t mailbox_from, u64_t msg_idnr, u64_t mailbox_to,
+	       u64_t user_idnr, u64_t * newmsg_idnr)
 {
 	u64_t msgsize;
 	char unique_id[UID_SIZE];
@@ -3833,9 +3857,9 @@ int db_copymsg(u64_t msg_idnr, u64_t mailbox_to, u64_t user_idnr,
 
 
 	/* Get the size of the message to be copied. */
-	if (! (msgsize = message_get_size(msg_idnr))) {
+	if (! (msgsize = message_get_size(mailbox_from, msg_idnr))) {
 		TRACE(TRACE_ERROR, "error getting message size for "
-		      "message [%" U64_T_FORMAT "]", msg_idnr);
+		      "mailbox [%" U64_T_FORMAT "] message [%" U64_T_FORMAT "]", mailbox_from, msg_idnr);
 		return DM_EQUERY;
 	}
 
@@ -3850,7 +3874,7 @@ int db_copymsg(u64_t msg_idnr, u64_t mailbox_to, u64_t user_idnr,
 		return -2;
 	}
 
-	create_unique_id(unique_id, msg_idnr);
+	create_unique_id(unique_id, mailbox_to, msg_idnr);
 
 	/* Copy the message table entry of the message. */
 	snprintf(query, DEF_QUERYSIZE,
@@ -3860,8 +3884,9 @@ int db_copymsg(u64_t msg_idnr, u64_t mailbox_to, u64_t user_idnr,
 		 "SELECT %" U64_T_FORMAT ", "
 		 "physmessage_id, seen_flag, answered_flag, deleted_flag, "
 		 "flagged_flag, recent_flag, draft_flag, '%s', status "
-		 "FROM %smessages WHERE message_idnr = %" U64_T_FORMAT,DBPFX,
-		 mailbox_to, unique_id,DBPFX, msg_idnr);
+		 "FROM %smessages WHERE mailbox_idnr = %" U64_T_FORMAT " AND message_idnr = %" U64_T_FORMAT " %s",
+		 DBPFX, mailbox_to, unique_id, DBPFX, mailbox_from, msg_idnr,
+		 db_returning("message_idnr"));
 
 	if (db_query(query) == -1) {
 		TRACE(TRACE_ERROR, "error copying message");
@@ -4914,9 +4939,10 @@ int db_user_create(const char *username, const char *password, const char *encty
 		snprintf(query, DEF_QUERYSIZE, "INSERT INTO %susers "
 			"(userid,user_idnr,passwd,client_idnr,maxmail_size,"
 			"encryption_type, last_login) VALUES "
-			"('%s',%" U64_T_FORMAT ",'%s',%" U64_T_FORMAT ",%" U64_T_FORMAT ",'%s', %s)",
+			"('%s',%" U64_T_FORMAT ",'%s',%" U64_T_FORMAT ",%" U64_T_FORMAT ",'%s', %s) %s",
 			DBPFX,escaped_username,*user_idnr, escaped_password,clientid, 
-			maxmail, enctype ? enctype : "", db_get_sql(SQL_CURRENT_TIMESTAMP));
+			maxmail, enctype ? enctype : "", db_get_sql(SQL_CURRENT_TIMESTAMP),
+			db_returning("user_idnr"));
 	}
 	g_free(escaped_username);
 	g_free(escaped_password);
diff --git a/db.h b/db.h
index e30ad712..bef7d4a3 100644
--- a/db.h
+++ b/db.h
@@ -177,6 +177,14 @@ u64_t db_get_result_u64(unsigned row, unsigned field);
 u64_t db_insert_result(const char *sequence_identifier);
 
 /**
+ * \brief generate a RETURNING clause applicable to the
+ *        current database backend.
+ * \param query SELECT-type clause of what to return
+ * \return string to append to INSERT or UPDATE query
+ */
+char *db_returning(char *query);
+
+/**
  * \brief escape a string for use in query
  * \param to string to copy escaped string to. Must be allocated by caller
  * \param from original string
@@ -302,18 +310,19 @@ int db_rollback_savepoint_transaction(const char*);
 
 /* shared implementattion from hereon */
 /**
- * \brief get the physmessage_id from a message_idnr
+ * \brief get the physmessage_id from a mailbox_idnr, message_idnr tuple
+ * \param mailbox_idnr
  * \param message_idnr
  * \param physmessage_id will hold physmessage_id on return. Must hold a valid
  * pointer on call.
  * \return 
  *     - -1 on error
  *     -  0 if a physmessage_id was found
- *     -  1 if no message with this message_idnr found
+ *     -  1 if no message with this mailbox_idnr, message_idnr tuple was found
  * \attention function will fail and halt program if physmessage_id is
  * NULL on call.
  */
-int db_get_physmessage_id(u64_t message_idnr, /*@out@*/ u64_t * physmessage_id);
+int db_get_physmessage_id(u64_t mailbox_idnr, u64_t message_idnr, /*@out@*/ u64_t * physmessage_id);
 
 /**
  * \brief return number of bytes used by user identified by userid
@@ -502,13 +511,14 @@ int db_get_reply_body(u64_t user_idnr, char **body);
 
 /**
  * \brief get user idnr of a message. 
+ * \param mailbox_idnr idnr of message
  * \param message_idnr idnr of message
  * \return 
  *              - -1 on failure
  * 		- 0 if message is located in a shared mailbox.
  * 		- user_idnr otherwise
  */
-u64_t db_get_useridnr(u64_t message_idnr);
+u64_t db_get_useridnr(u64_t mailbox_idnr, u64_t message_idnr);
 
 /**
  * \brief insert a new physmessage. This inserts only an new record in the
@@ -536,6 +546,7 @@ int db_insert_physmessage_with_internal_date(timestring_t internal_date,
 /**
  * \brief update unique_id, message_size and rfc_size of
  *        a message identified by message_idnr
+ * \param mailbox_idnr
  * \param message_idnr
  * \param unique_id unique id of message
  * \param message_size size of message
@@ -544,17 +555,18 @@ int db_insert_physmessage_with_internal_date(timestring_t internal_date,
  *      - -1 on database error
  *      - 0 on success
  */
-int db_update_message(u64_t message_idnr, const char *unique_id,
+int db_update_message(u64_t mailbox_idnr, u64_t message_idnr, const char *unique_id,
 		      u64_t message_size, u64_t rfc_size);
 /**
  * \brief set unique id of a message 
+ * \param mailbox_idnr
  * \param message_idnr
  * \param unique_id unique id of message
  * \return 
  *     - -1 on database error
  *     -  0 on success
  */
-int db_message_set_unique_id(u64_t message_idnr, const char *unique_id);
+int db_message_set_unique_id(u64_t mailbox_idnr, u64_t message_idnr, const char *unique_id);
 
 /**
  * \brief set messagesize and rfcsize of a message
@@ -588,6 +600,7 @@ int db_insert_message_block_physmessage(const char *block,
 * \brief insert a message block into the message block table
 * \param block the message block (which is a string)
 * \param block_size length of the block
+* \param mailbox_idnr mailbox of the message the block belongs to
 * \param message_idnr id of the message the block belongs to
 * \param messageblock_idnr will hold id of messageblock after call. Should
 * be a valid pointer on call.
@@ -596,6 +609,7 @@ int db_insert_message_block_physmessage(const char *block,
 *        - 0 otherwise
 */
 int db_insert_message_block(const char *block, u64_t block_size,
+			    u64_t mailbox_idnr,
 			    u64_t message_idnr, /*@out@*/ u64_t *physmessage_id,
 			    /*@out@*/ u64_t * messageblock_idnr,
 			    unsigned is_header);
@@ -751,11 +765,12 @@ int db_icheck_envelope(GList **lost);
 int db_set_envelope(GList *lost);
 /**
  * \brief set status of a message
+ * \param mailbox_idnr
  * \param message_idnr
  * \param status new status of message
  * \return result of db_query()
  */
-int db_set_message_status(u64_t message_idnr, MessageStatus_t status);
+int db_set_message_status(u64_t mailbox_idnr, u64_t message_idnr, MessageStatus_t status);
 
 /**
 * \brief delete a message block
@@ -774,12 +789,13 @@ int db_delete_physmessage(u64_t physmessage_id);
 
 /**
  * \brief delete a message 
+ * \param mailbox_idnr
  * \param message_idnr
  * \return 
  *     - -1 on error
  *     -  1 on success
  */
-int db_delete_message(u64_t message_idnr);
+int db_delete_message(u64_t mailbox_idnr, u64_t message_idnr);
 
 /**
  * \brief delete a mailbox. 
@@ -799,6 +815,7 @@ int db_delete_mailbox(u64_t mailbox_idnr, int only_empty,
 /**
  * \brief write lines of message to fstream. Always write full headers.
  * \param fstream the stream to write to
+ * \param mailbox_idnr mailbox of message to write
  * \param message_idnr idrn of message to write
  * \param lines number of lines to write. If <PRE>lines == -2</PRE>, then
  *              the whole message (excluding the header) is written.
@@ -810,7 +827,7 @@ int db_delete_mailbox(u64_t mailbox_idnr, int only_empty,
  * 		- 0 on failure
  * 		- 1 on success
  */
-int db_send_message_lines(void *fstream, u64_t message_idnr,
+int db_send_message_lines(void *fstream, u64_t mailbox_idnr, u64_t message_idnr,
 			  long lines, int no_end_dot);
 /**
  * \brief create a new POP3 session. (was createsession() in dbmysql.c)
@@ -1093,6 +1110,7 @@ int db_removemsg(u64_t user_idnr, u64_t mailbox_idnr);
 int db_movemsg(u64_t mailbox_to, u64_t mailbox_from);
 /**
  * \brief copy a message to a mailbox
+ * \param mailbox_from mailbox to copy from
  * \param msg_idnr
  * \param mailbox_to mailbox to copy to
  * \param user_idnr user to copy the messages for.
@@ -1101,7 +1119,7 @@ int db_movemsg(u64_t mailbox_to, u64_t mailbox_from);
  * 		- -1 on failure
  * 		- 0 on success
  */
-int db_copymsg(u64_t msg_idnr, u64_t mailbox_to,
+int db_copymsg(u64_t mailbox_from, u64_t msg_idnr, u64_t mailbox_to,
 	       u64_t user_idnr, u64_t * newmsg_idnr);
 
 /**
diff --git a/dbmail-imapsession.c b/dbmail-imapsession.c
index f444452f..aa25d057 100644
--- a/dbmail-imapsession.c
+++ b/dbmail-imapsession.c
@@ -362,7 +362,7 @@ static u64_t _imap_cache_update(struct ImapSession *self, message_filter_t filte
 			cached_msg.dmsg = NULL;
 		}
 
-		cached_msg.dmsg = db_init_fetch(self->msg_idnr, DBMAIL_MESSAGE_FILTER_FULL);
+		cached_msg.dmsg = db_init_fetch(self->mailbox->id, self->msg_idnr, DBMAIL_MESSAGE_FILTER_FULL);
 		buf = dbmail_message_to_string(cached_msg.dmsg);
 	
 		outcnt = _imap_cache_set_dump(buf,IMAP_CACHE_MEMDUMP);
@@ -2078,12 +2078,15 @@ int dbmail_imap_session_mailbox_close(struct ImapSession *self)
 	return 0;
 }
 
-static int imap_session_update_recent(GList *recent) 
+static int imap_session_update_recent(struct DbmailMailbox *mailbox, GList *recent) 
 {
 	GList *slices, *topslices;
 	char query[DEF_QUERYSIZE];
 	memset(query,0,DEF_QUERYSIZE);
 
+	if (mailbox == NULL)
+		return 0;
+
 	if (recent == NULL)
 		return 0;
 
@@ -2093,8 +2096,8 @@ static int imap_session_update_recent(GList *recent)
 	db_begin_transaction();
 	while (slices) {
 		snprintf(query, DEF_QUERYSIZE, "UPDATE %smessages SET recent_flag = 0 "
-				"WHERE message_idnr IN (%s) AND recent_flag = 1", 
-				DBPFX, (gchar *)slices->data);
+				"WHERE mailbox_idnr = %" U64_T_FORMAT " AND message_idnr IN (%s) AND recent_flag = 1", 
+			 DBPFX, mailbox->id, (gchar *)slices->data);
 		if (db_query(query) == -1) {
 			db_rollback_transaction();
 			return (-1);
@@ -2111,7 +2114,7 @@ static int imap_session_update_recent(GList *recent)
 
 int dbmail_imap_session_mailbox_update_recent(struct ImapSession *self) 
 {
-	imap_session_update_recent(self->recent);
+	imap_session_update_recent(self->mailbox, self->recent);
 	g_list_destroy(self->recent);
 	self->recent = NULL;
 
diff --git a/dbmail-mailbox.c b/dbmail-mailbox.c
index 29911e0d..eaaaa198 100644
--- a/dbmail-mailbox.c
+++ b/dbmail-mailbox.c
@@ -326,10 +326,10 @@ int dbmail_mailbox_dump(struct DbmailMailbox *self, FILE *file)
 		g_string_printf(q,"SELECT is_header,messageblk,%s FROM %smessageblks b "
 				"JOIN %sphysmessage p ON b.physmessage_id = p.id "
 				"JOIN %smessages m ON m.physmessage_id = p.id "
-				"WHERE message_idnr IN (%s) "
+				"WHERE mailbox_idnr = %" U64_T_FORMAT " AND message_idnr IN (%s) "
 				"ORDER BY messageblk_idnr ",
 				date2char,
-				DBPFX, DBPFX, DBPFX,
+				DBPFX, DBPFX, DBPFX, self->id,
 				(char *)slice->data);
 		
 		if (db_query(q->str) == -1) {
diff --git a/dbmail-message.c b/dbmail-message.c
index e56afc35..0465a90e 100644
--- a/dbmail-message.c
+++ b/dbmail-message.c
@@ -811,7 +811,7 @@ int dbmail_message_store(struct DbmailMessage *self)
 		break;
 	}
 
-	create_unique_id(unique_id, user_idnr);
+	create_unique_id(unique_id, user_idnr, user_idnr);
 	/* create a message record */
 	if(_message_insert(self, user_idnr, DBMAIL_TEMPMBOX, unique_id) < 0)
 		return -1;
@@ -829,7 +829,7 @@ int dbmail_message_store(struct DbmailMessage *self)
 
 	hdrs = dbmail_message_hdrs_to_string(self);
 	hdrs_size = (u64_t)dbmail_message_get_hdrs_size(self, FALSE);
-	if(db_insert_message_block(hdrs, hdrs_size, self->id, &physmessage_id, &messageblk_idnr,1) < 0) {
+	if(db_insert_message_block(hdrs, hdrs_size, self->mailbox, self->id, &physmessage_id, &messageblk_idnr,1) < 0) {
 		g_free(hdrs);
 		return -1;
 	}
@@ -838,14 +838,14 @@ int dbmail_message_store(struct DbmailMessage *self)
 	/* store body in several blocks (if needed */
 	body = dbmail_message_body_to_string(self);
 	body_size = (u64_t)dbmail_message_get_body_size(self, FALSE);
-	if (store_message_in_blocks(body, body_size, self->id, physmessage_id) < 0) {
+	if (store_message_in_blocks(body, body_size, self->mailbox, self->id, physmessage_id) < 0) {
 		g_free(body);
 		return -1;
 	}
 	g_free(body);
 
 	rfcsize = (u64_t)dbmail_message_get_rfcsize(self);
-	if (db_update_message(self->id, unique_id, (hdrs_size + body_size), rfcsize) < 0)
+	if (db_update_message(self->mailbox, self->id, unique_id, (hdrs_size + body_size), rfcsize) < 0)
 		return -1;
 
 	/* store message headers */
@@ -899,15 +899,16 @@ int _message_insert(struct DbmailMessage *self,
 	snprintf(query, DEF_QUERYSIZE, "INSERT INTO "
 		 "%smessages(mailbox_idnr, physmessage_id, unique_id,"
 		 "recent_flag, status) "
-		 "VALUES (%" U64_T_FORMAT ", %" U64_T_FORMAT ", '%s', 1, %d)",
+		 "VALUES (%" U64_T_FORMAT ", %" U64_T_FORMAT ", '%s', 1, %d) %s",
 		 DBPFX, mailboxid, physmessage_id, unique_id,
-		 MESSAGE_STATUS_INSERT);
+		 MESSAGE_STATUS_INSERT, db_returning("message_idnr"));
 
 	if (db_query(query) == -1) {
 		TRACE(TRACE_ERROR, "query failed");
 		return -1;
 	}
 
+	self->mailbox = mailboxid;
 	self->id = db_insert_result("message_idnr");
 	return 1;
 }
@@ -969,7 +970,7 @@ static int _header_get_id(const struct DbmailMessage *self, const char *header,
 	}
 	if (db_num_rows() < 1) {
 		db_free_result();
-		g_string_printf(q, "INSERT INTO %sheadername (headername) VALUES ('%s')", DBPFX, safe_header);
+		g_string_printf(q, "INSERT INTO %sheadername (headername) VALUES ('%s') %s", DBPFX, safe_header, db_returning("id"));
 		if (db_query(q->str) == -1) {
 			g_string_free(q,TRUE);
 			g_free(safe_header);
@@ -1002,6 +1003,19 @@ static gboolean _header_cache(const char UNUSED *key, const char *header, gpoint
 	if (strchr(header, ' '))
 		return FALSE;
 
+	/* only cache the headers nnimap needs: */
+	/* subject from date message-id references in-reply-to xref to newsgroups */
+//	if (strcasecmp(header, "to"))
+//	    if (strcasecmp(header, "date"))
+//		if (strcasecmp(header, "from"))
+//		    if (strcasecmp(header, "subject"))
+//			if (strcasecmp(header, "message-id"))
+//			    if (strcasecmp(header, "references"))
+//				if (strcasecmp(header, "in-reply-to"))
+//				    if (strcasecmp(header, "newsgroups"))
+//					if (strcasecmp(header, "xref"))
+//					    return FALSE;
+
 	if ((_header_get_id(self, header, &id) < 0))
 		return TRUE;
 
@@ -1392,13 +1406,13 @@ struct DbmailMessage * dbmail_message_construct(struct DbmailMessage *self,
 
 /* old stuff moved here from dbmsgbuf.c */
 
-struct DbmailMessage * db_init_fetch(u64_t msg_idnr, int filter)
+struct DbmailMessage * db_init_fetch(u64_t mailbox_idnr, u64_t msg_idnr, int filter)
 {
 	struct DbmailMessage *msg;
 
 	int result;
 	u64_t physid = 0;
-	if ((result = db_get_physmessage_id(msg_idnr, &physid)) != DM_SUCCESS)
+	if ((result = db_get_physmessage_id(mailbox_idnr, msg_idnr, &physid)) != DM_SUCCESS)
 		return NULL;
 	msg = dbmail_message_new();
 	if (! (msg = dbmail_message_retrieve(msg, physid, filter)))
diff --git a/dbmail-message.h b/dbmail-message.h
index 979c105a..7240ad50 100644
--- a/dbmail-message.h
+++ b/dbmail-message.h
@@ -61,6 +61,7 @@ typedef enum DBMAIL_STREAM_TYPE {
 } dbmail_stream_t;
 
 struct DbmailMessage {
+	u64_t mailbox;
 	u64_t id;
 	u64_t physid;
 	time_t internal_date;
@@ -172,7 +173,7 @@ char * g_mime_object_get_body(const GMimeObject *object);
  *     -  1 on success
  */
 
-struct DbmailMessage * db_init_fetch(u64_t msg_idnr, int filter);
+struct DbmailMessage * db_init_fetch(u64_t mailbox_idnr, u64_t msg_idnr, int filter);
 
 #define db_init_fetch_headers(x) db_init_fetch(x,DBMAIL_MESSAGE_FILTER_HEAD)
 #define db_init_fetch_message(x) db_init_fetch(x,DBMAIL_MESSAGE_FILTER_FULL)
diff --git a/dbmailtypes.h b/dbmailtypes.h
index 3bfe912b..8af524ec 100644
--- a/dbmailtypes.h
+++ b/dbmailtypes.h
@@ -146,6 +146,7 @@ typedef struct {
 /** all virtual_ definitions are session specific
  *  when a RSET occurs all will be set to the real values */
 struct message {
+	u64_t mailbox;	  /**< mailbox idnr */
 	u64_t msize;	  /**< message size */
 	u64_t messageid;  /**< messageid (from database) */
 	u64_t realmessageid;
@@ -191,8 +192,9 @@ typedef struct {
 	char *apop_stamp; /**< timestamp for APOP */
 
 	u64_t useridnr;	/**< Used by timsieved */
+	u64_t mailbox_idnr;
 
-	u64_t totalsize;/**< total size of messages */
+	u64_t totalsize; /**< total size of messages */
 	u64_t virtual_totalsize;
 	u64_t totalmessages; /**< number of messages */
 	u64_t virtual_totalmessages;
@@ -524,5 +526,9 @@ typedef enum {
 	IMAP_FLAG_RECENT
 } imap_flag_t;
 
+typedef struct box_uid {
+    u64_t mailbox;
+    u64_t uid;
+} box_uid_t;
 
 #endif
diff --git a/dbmodule.c b/dbmodule.c
index faff1909..aacf9ea6 100644
--- a/dbmodule.c
+++ b/dbmodule.c
@@ -85,6 +85,7 @@ int db_load_driver(void)
 	||  !g_module_symbol(module, "db_disconnect",          (gpointer)&db->disconnect          )
 	||  !g_module_symbol(module, "db_check_connection",    (gpointer)&db->check_connection    )
 	||  !g_module_symbol(module, "db_query",               (gpointer)&db->query               )
+	||  !g_module_symbol(module, "db_returning",           (gpointer)&db->returning           )
 	||  !g_module_symbol(module, "db_insert_result",       (gpointer)&db->insert_result       )
 	||  !g_module_symbol(module, "db_num_rows",            (gpointer)&db->num_rows            )
 	||  !g_module_symbol(module, "db_num_fields",          (gpointer)&db->num_fields          )
@@ -153,6 +154,8 @@ int db_query(const char *the_query)
 
 	return result;
 }
+char * db_returning(char *query)
+	{ return db->returning(query); }
 u64_t db_insert_result(const char *sequence_identifier)
 	{ return db->insert_result(sequence_identifier); }
 unsigned db_num_rows(void)
diff --git a/dbmodule.h b/dbmodule.h
index e3f8aa12..847bbb98 100644
--- a/dbmodule.h
+++ b/dbmodule.h
@@ -16,6 +16,7 @@ typedef struct {
 	int (* disconnect)(void);
 	int (* check_connection)(void);
 	int (* query)(const char *the_query);
+	char * (* returning)(char *query);
 	u64_t (* insert_result)(const char *sequence_identifier);
 	unsigned (* num_rows)(void);
 	unsigned (* num_fields)(void);
diff --git a/export.c b/export.c
index cfb2fd30..e7cffe4c 100644
--- a/export.c
+++ b/export.c
@@ -141,7 +141,7 @@ static int mailbox_dump(u64_t mailbox_idnr, const char *dumpfile,
 			// Set deleted status on each message
 			// Following this, dbmail-util -p sets purge status
 			if (delete_after_dump & 2) {
-				if (db_set_message_status(*(u64_t *)ids->data, MESSAGE_STATUS_DELETE)) {
+				if (db_set_message_status(mailbox_idnr, *(u64_t *)ids->data, MESSAGE_STATUS_DELETE)) {
 					qerrorf("Error setting status for message [%" U64_T_FORMAT "]\n", *(u64_t *)ids->data);
 					result = -1;
 				}
diff --git a/imapcommands.c b/imapcommands.c
index 26fecc64..1d3dcf36 100644
--- a/imapcommands.c
+++ b/imapcommands.c
@@ -1756,7 +1756,7 @@ static gboolean _do_copy(u64_t *id, gpointer UNUSED value, struct ImapSession *s
 	u64_t newid;
 	int result;
 
-	result = db_copymsg(*id, cmd->mailbox_id, ud->userid, &newid);
+	result = db_copymsg(self->mailbox->id, *id, cmd->mailbox_id, ud->userid, &newid);
 	if (result == -1) {
 		dbmail_imap_session_printf(self, "* BYE internal dbase error\r\n");
 		db_rollback_transaction();
diff --git a/maintenance.c b/maintenance.c
index 6467905e..d2423b4a 100644
--- a/maintenance.c
+++ b/maintenance.c
@@ -461,12 +461,14 @@ int do_dangling_aliases(void)
 	return result;
 }
 
+/* FIXME: lostlist needs to be of pairs of ints rather than of ints */
+/*        figure out how to recover the individual pairs            */
 int do_null_messages(void)
 {
 	time_t start, stop;
 	struct dm_list lostlist;
 	struct element *el;
-	u64_t id;
+	u64_t mailbox, id;
 
 	if (no_to_all) {
 		qprintf("\nChecking DBMAIL for NULL messages...\n");
@@ -494,11 +496,12 @@ int do_null_messages(void)
 		if (lostlist.total_nodes > 0) {
 			el = lostlist.start;
 			while (el) {
-				id = *((u64_t *) el->data);
-				if (db_set_message_status(id, MESSAGE_STATUS_ERROR) < 0)
-					qerrorf("Warning: could not set status on message [%" U64_T_FORMAT "]. Check log.\n", id);
+				mailbox = ((box_uid_t *) el->data)->mailbox;
+				id      = ((box_uid_t *) el->data)->uid;
+				if (db_set_message_status(mailbox, id, MESSAGE_STATUS_ERROR) < 0)
+					qerrorf("Warning: could not set status on mailbox [%" U64_T_FORMAT "] message [%" U64_T_FORMAT "]. Check log.\n", mailbox, id);
 				else
-					qverbosef("[%" U64_T_FORMAT "] set to MESSAGE_STATUS_ERROR)\n", id);
+					qverbosef("[%" U64_T_FORMAT "/%" U64_T_FORMAT "] set to MESSAGE_STATUS_ERROR)\n", mailbox, id);
         
 				el = el->nextnode;
 			}
@@ -551,7 +554,7 @@ int do_check_integrity(void)
 	struct element *el;
 	const char *action;
 	int count = 0;
-	u64_t id;
+	u64_t mailbox, id;
 
 	if (yes_to_all)
 		action = "Repairing";
@@ -664,12 +667,13 @@ int do_check_integrity(void)
 		if (lostlist.total_nodes > 0) {
 			el = lostlist.start;
 			while (el) {
-				id = *((u64_t *) el->data);
+				mailbox = ((box_uid_t *) el->data)->mailbox;
+				id      = ((box_uid_t *) el->data)->uid;
         
 				if (no_to_all) {
 					qerrorf("%" U64_T_FORMAT " ", id);
 				} else if (yes_to_all) {
-					if (db_delete_message(id) < 0)
+					if (db_delete_message(mailbox,id) < 0)
 						qerrorf
 						    ("Warning: could not delete message #%" U64_T_FORMAT ". Check log.\n",
 						     id);
diff --git a/misc.c b/misc.c
index c696b973..0db89326 100644
--- a/misc.c
+++ b/misc.c
@@ -95,17 +95,18 @@ int drop_privileges(char *newuser, char *newgroup)
 	return 0;
 }
 
-void create_unique_id(char *target, u64_t message_idnr)
+void create_unique_id(char *target, u64_t mailbox_idnr, u64_t message_idnr)
 {
-	char *a_message_idnr, *a_rand;
+	char *a_mailbox_idnr, *a_message_idnr, *a_rand;
 	char *md5_str;
 
+	a_mailbox_idnr = g_strdup_printf("%" U64_T_FORMAT,mailbox_idnr);
 	a_message_idnr = g_strdup_printf("%" U64_T_FORMAT,message_idnr);
 	a_rand = g_strdup_printf("%d",g_random_int());
 
 	if (message_idnr != 0)
-		snprintf(target, UID_SIZE, "%s:%s",
-			 a_message_idnr, a_rand);
+		snprintf(target, UID_SIZE, "%s:%s:%s",
+			 a_mailbox_idnr, a_message_idnr, a_rand);
 	else
 		snprintf(target, UID_SIZE, "%s", a_rand);
 	md5_str = dm_md5((unsigned char *)target);
diff --git a/misc.h b/misc.h
index 5993a6ff..51827d6a 100644
--- a/misc.h
+++ b/misc.h
@@ -40,9 +40,10 @@ int drop_privileges(char *newuser, char *newgroup);
 /**
  * \brief create a unique id for a message (used for pop, stored per message)
  * \param target target string. Length should be UID_SIZE 
+ * \param message_idnr mailbox_idnr of message
  * \param message_idnr message_idnr of message
  */
-void create_unique_id(/*@out@*/ char *target, u64_t message_idnr);
+void create_unique_id(/*@out@*/ char *target, u64_t mailbox_idnr, u64_t message_idnr);
 
 /**
  * \brief create a timestring with the current time.
diff --git a/modules/dbmysql.c b/modules/dbmysql.c
index c86287d9..f8a7da4b 100644
--- a/modules/dbmysql.c
+++ b/modules/dbmysql.c
@@ -369,3 +369,8 @@ void db_set_result_set(void *the_result_set)
 	res = (MYSQL_RES *) the_result_set;
 	res_changed = 1;
 }
+
+char *db_returning(char *query)
+{
+	return g_new0(char, 1);
+}
diff --git a/modules/dbpgsql.c b/modules/dbpgsql.c
index 26eec757..bfecbe11 100644
--- a/modules/dbpgsql.c
+++ b/modules/dbpgsql.c
@@ -243,23 +243,17 @@ const char *db_get_result(unsigned row, unsigned field)
 	return PQgetvalue(res, row, field);
 }
 
+/* get the result of the RETURNING clause added
+ * by way of db_returning() */
 u64_t db_insert_result(const char *sequence_identifier)
 {
-	char query[DEF_QUERYSIZE];
-	memset(query,0,DEF_QUERYSIZE);
-
 	u64_t insert_result;
 
-	/* postgres uses the currval call on a sequence to determine
-	 * the result value of an insert query */
-	snprintf(query, DEF_QUERYSIZE,
-		 "SELECT currval('%s%s_seq')",_db_params.pfx, sequence_identifier);
-
-	db_query(query);
 	if (db_num_rows() == 0) {
 		db_free_result();
 		return 0;
 	}
+
 	insert_result = strtoull(db_get_result(0, 0), NULL, 10);
 	db_free_result();
 	return insert_result;
@@ -365,3 +359,12 @@ void db_set_result_set(void *the_result_set)
 {
 	res = (PGresult *) the_result_set;
 }
+
+char *db_returning(char *query)
+{
+	unsigned bufferlen = 10 + strlen(query) + 1;
+	char *buffer = g_new0(char, bufferlen);
+	snprintf(buffer, bufferlen,
+		"RETURNING %s", query);
+	return buffer;
+}
diff --git a/modules/dbsqlite.c b/modules/dbsqlite.c
index 94d8d566..6bd31371 100644
--- a/modules/dbsqlite.c
+++ b/modules/dbsqlite.c
@@ -391,3 +391,8 @@ void db_set_result_set(void *the_result_set)
 {
 	lastq = (struct qtmp *)the_result_set;
 }
+
+char *db_returning(char *query)
+{
+	return g_new0(char, 1);
+}
diff --git a/pipe.c b/pipe.c
index 1482e4d0..66c7b01b 100644
--- a/pipe.c
+++ b/pipe.c
@@ -502,7 +502,7 @@ static int execute_auto_ran(struct DbmailMessage *message, u64_t useridnr)
 
 
 int store_message_in_blocks(const char *message, u64_t message_size,
-			    u64_t msgidnr, u64_t physmsg_id) 
+			    u64_t mailbox, u64_t msgidnr, u64_t physmsg_id) 
 {
 	u64_t tmp_messageblk_idnr;
 	u64_t rest_size = message_size;
@@ -516,9 +516,9 @@ int store_message_in_blocks(const char *message, u64_t message_size,
 			      rest_size : READ_BLOCK_SIZE);
 		rest_size = (rest_size < READ_BLOCK_SIZE ?
 			     0 : rest_size - READ_BLOCK_SIZE);
-		TRACE(TRACE_DEBUG, "inserting message: size [%llu] block[%d]", message_size, block_nr);
+		TRACE(TRACE_DEBUG, "inserting message: size [%" U64_T_FORMAT "] block[%d]", message_size, block_nr);
 		if (db_insert_message_block(&message[offset],
-					    block_size, msgidnr, &physmsg_id,
+					    block_size, mailbox, msgidnr, &physmsg_id,
 					    &tmp_messageblk_idnr,0) < 0) {
 			TRACE(TRACE_ERROR, "db_insert_message_block() failed");
 			return -1;
@@ -568,7 +568,7 @@ int insert_messages(struct DbmailMessage *message,
 		struct dm_list *dsnusers)
 {
 	u64_t bodysize, rfcsize;
-	u64_t tmpid;
+	u64_t tmpbox, tmpid;
 	struct element *element;
 	u64_t msgsize;
 
@@ -593,7 +593,9 @@ int insert_messages(struct DbmailMessage *message,
 	if (db_commit_transaction() < 0) 
 		return -1;
 
-	tmpid = message->id; // for later removal
+	/* for later removal */
+	tmpbox = message->mailbox;
+	tmpid  = message->id;
 
 	bodysize = (u64_t)dbmail_message_get_body_size(message, FALSE);
 	rfcsize = (u64_t)dbmail_message_get_rfcsize(message);
@@ -702,7 +704,7 @@ int insert_messages(struct DbmailMessage *message,
 	/* Always delete the temporary message, even if the delivery failed.
 	 * It is the MTA's job to requeue or bounce the message,
 	 * and our job to keep a tidy database ;-) */
-	if (db_delete_message(tmpid) < 0) 
+	if (db_delete_message(tmpbox, tmpid) < 0) 
 		TRACE(TRACE_ERROR, "failed to delete temporary message [%" U64_T_FORMAT "]", message->id);
 	TRACE(TRACE_DEBUG, "temporary message deleted from database. Done.");
 
@@ -755,7 +757,8 @@ int send_alert(u64_t user_idnr, char *subject, char *body)
 
 	// Pre-insert the message and get a new_message->id
 	dbmail_message_store(new_message);
-	u64_t tmpid = new_message->id;
+	u64_t tmpbox = new_message->mailbox;
+	u64_t tmpid  = new_message->id;
 
 	if (sort_deliver_to_mailbox(new_message, user_idnr,
 			"INBOX", BOX_BRUTEFORCE, msgflags) != DSN_CLASS_OK) {
@@ -763,7 +766,7 @@ int send_alert(u64_t user_idnr, char *subject, char *body)
 	}
 
 	g_free(to);
-	db_delete_message(tmpid);
+	db_delete_message(tmpbox, tmpid);
 	dbmail_message_free(new_message);
 
 	return 0;
diff --git a/pipe.h b/pipe.h
index ef7806f7..5b074e8d 100644
--- a/pipe.h
+++ b/pipe.h
@@ -41,6 +41,7 @@ int insert_messages(struct DbmailMessage *message, struct dm_list *dsnusers);
  */
 int store_message_in_blocks(const char* message,
 				   u64_t message_size,
+				   u64_t mailbox,
 				   u64_t msgidnr,
 				   u64_t physmsg_id);
 
diff --git a/pop3.c b/pop3.c
index 4f757cd4..88c435db 100644
--- a/pop3.c
+++ b/pop3.c
@@ -92,7 +92,7 @@ int pop3_handle_connection(clientinfo_t * ci)
 	
 	/* create an unique timestamp + processid for APOP authentication */
 	session.apop_stamp = g_new0(char,APOP_STAMP_SIZE);
-	create_unique_id(unique_id, 0);
+	create_unique_id(unique_id, 0, 0);
 	snprintf(session.apop_stamp, APOP_STAMP_SIZE, "<%s@%s>", unique_id, myhostname);
 
 	if (ci->tx) {
@@ -509,7 +509,7 @@ int pop3(clientinfo_t *ci, char *buffer, PopSession_t * session)
 			if (msg->messageid == strtoull(value, NULL, 10) && msg->virtual_messagestatus < MESSAGE_STATUS_DELETE) {	/* message is not deleted */
 				msg->virtual_messagestatus = MESSAGE_STATUS_SEEN;
 				ci_write((FILE *) stream, "+OK %" U64_T_FORMAT " octets\r\n", msg->msize);
-				return db_send_message_lines((void *) stream, msg->realmessageid, -2, 0);
+				return db_send_message_lines((void *) stream, session->mailbox_idnr, msg->realmessageid, -2, 0);
 			}
 			tmpelement = tmpelement->nextnode;
 		}
@@ -769,7 +769,7 @@ int pop3(clientinfo_t *ci, char *buffer, PopSession_t * session)
 			msg = (struct message *) tmpelement->data;
 			if (msg->messageid == top_messageid && msg->virtual_messagestatus < MESSAGE_STATUS_DELETE) {	/* message is not deleted */
 				ci_write((FILE *) stream, "+OK %" U64_T_FORMAT " lines of message %" U64_T_FORMAT "\r\n", top_lines, top_messageid);
-				return db_send_message_lines(stream, msg->realmessageid, top_lines, 0);
+				return db_send_message_lines(stream, session->mailbox_idnr, msg->realmessageid, top_lines, 0);
 			}
 			tmpelement = tmpelement->nextnode;
 		}
diff --git a/sort.c b/sort.c
index bf2bedee..ebe52e83 100644
--- a/sort.c
+++ b/sort.c
@@ -182,7 +182,7 @@ dsn_class_t sort_deliver_to_mailbox(struct DbmailMessage *message,
 	}
 
 	// Ok, we have the ACL right, time to deliver the message.
-	switch (db_copymsg(message->id, mboxidnr, useridnr, &newmsgidnr)) {
+	switch (db_copymsg(message->mailbox, message->id, mboxidnr, useridnr, &newmsgidnr)) {
 	case -2:
 		TRACE(TRACE_DEBUG, "error copying message to user [%" U64_T_FORMAT "],"
 				"maxmail exceeded", useridnr);
@@ -192,14 +192,15 @@ dsn_class_t sort_deliver_to_mailbox(struct DbmailMessage *message,
 				useridnr);
 		return DSN_CLASS_TEMP;
 	default:
-		TRACE(TRACE_MESSAGE, "message id=%" U64_T_FORMAT ", size=%zd is inserted", 
-				newmsgidnr, msgsize);
+		TRACE(TRACE_MESSAGE, "message id=%" U64_T_FORMAT ", size=%zd is inserted to mailbox id=%" U64_T_FORMAT "", 
+				newmsgidnr, msgsize, mboxidnr);
 		if (msgflags) {
-			TRACE(TRACE_MESSAGE, "message id=%" U64_T_FORMAT ", setting imap flags", 
-				newmsgidnr);
+			TRACE(TRACE_MESSAGE, "mbox id=%" U64_T_FORMAT ", message id=%" U64_T_FORMAT ", setting imap flags", 
+				mboxidnr, newmsgidnr);
 			db_set_msgflag(newmsgidnr, mboxidnr, msgflags, IMAPFA_ADD);
 		}
 		message->id = newmsgidnr;
+		message->mailbox = mboxidnr;
 		return DSN_CLASS_OK;
 	}
 }