Monitoring Mail Server Message Queue and Troubleshooting Mail Congestion
If your customers complain that they cannot send e-mail through your mail server, this can mean that your mail server is overloaded and cannot cope with the amount of received messages. This can happen when somebody is sending spam through your mail server, or the qmail-send daemon responsible for sending mail is down.
To return your mail server to an operable state, delete the unwanted messages from the mail server's message queue and then restart the mail server.
To see the messages in the message queue and to delete them:
- Click the Server shortcut in the navigation pane.
- Click
Mail icon in the Services group. - Click the Mail Queue tab. The following information will be presented:
- Total number of undelivered messages. When messages come to your mail server they are first added to the main queue. Then, the mail server preprocesses them in order to find out whether they should be delivered to a local e-mail account on the same server or sent further to a remote recipient's e-mail address. After preprocessing, the messages directed at local mail recipients are put to a local queue, and the messages directed at remote recipients are put to a remote queue. Once delivered, the messages are removed from the queues.
- Message properties: subject, sender, recipient, queue type (local, remote, not preprocessed), date the message was sent from user's computer, the time lapsed since the moment when message was put to queue (age), and message size.
- To find a message with specific subject, select the queue in the Queues drop-down box, type the desired combination of symbols into the Subject box, and click Search. The messages matching your search criteria will be listed at the bottom of the screen. To reset the filter, click Show All.
- To find a message from a specific sender, click the Show Advanced link, type the sender's e-mail address into the Envelope Sender box, and click Search. The messages matching your search criteria will be listed at the bottom of the screen. To reset the filter, click Show All.
- To find a message addressed to a specific recipient, click the Show Advanced link, type the recipient's e-mail address into the Recipients box, and click Search. The messages matching your search criteria will be listed at the bottom of the screen. To reset the filter, click Show All.
- To find a message by date, age, or size, click the Show Advanced link, type the required values into the Date, Age, or Size boxes, respectively, and click Search. The messages matching your search criteria will be listed at the bottom of the screen. To reset the filter, click Show All.
- To delete a message from the queue, select the corresponding check box and click
Remove Selected. To delete all messages from the queue, select the check box in the upper-right corner of the messages list, and click
Remove Selected.
To restart the mail server:
- Click the Server shortcut in the navigation pane.
- Click the
Service Management icon in the Services group. - Click the
Restart icon corresponding to the SMTP Server (QMail) entry.