|MithiWiki Home > ConnectXf Home > ConnectXf Administration > Configuration > Mail queues growing consistently on the server|
Mail queues growing consistently on the server.
This typically happens when the server is not able to effectively connect to the recipient server, and it has to defer the mail in the queue for another attempt later. A closer inspection of the maillog may show lines with "connection died".
For an Internet relay server: (one to many connections. This server directly relays mail to Internet domain servers) This is not uncommon when the server is a relay server and is directly connecting to recipient servers over the Internet to deliver mail. Its quite possible that the server it is attempting to connect to, may be busy or unavailable at that moment. If the queues continue to pile up, then it could indicate a problem in the core connectivity of the site to the Internet.
For an relay server to an ISP MTA (one to one connection. This server relays mail to another MTA which in turn delivers to the recipients) However if the relay is configured to send mail via another MTA in the chain, typically at an ISP site, then the connections are only one to one normally. Here we need to isolate two possible causes:
- That the ISP mail server is busy or unavailable.
- Test this using a SMTP telnet session to the ISP mail server.
- That the Internet link between the two is available in and in good quality.
- Check in /var/log/maillog to see if at all or only some of the mail are being dropped. If all are being dropped, then it indicates a dead connection. If some are being delivered and some are being dropped, then it indicates a low quality connection with intermittent behaviour.
A setup which has an archival server In the mail flow, there is a 'tap' for sending the mail to the Archival server, which means that this is inline with the flow. In case the archival server is not responding, the mail will be held in the queue. Confirm that the SMTP service on the Archive server is up, and is responding. Sometimes the archive system may be overloaded while trying to index a very large mail (unzip the attachments and then work on them), which may take a very long time if the mail size is in MBs. Confirm that the archive system is configured with a respectable max mail size and also that the archive system is running with a decent memory allocation.