Monday, August 12, 2013, 13:05
Solution ID: 00000228
There are messages stuck in the PerfectMail mail queue. How can I change how long they are stuck there?
E-mail delivery can be complex and depends on the e-mail priority, the type of return code (error message) generated by the remote mail server and local policies for attempting to resend an e-mail. Error conditions that are considered permanent (e.g. a bad recipient, non-existent recipient, spam, etc.) result in an immediate return of the e-mail to the sender. Temporary or transient errors result in the e-mail staying in the mail queue and transmission is retried for a period of time. Keep in mind, delivery delays are not uncommon and reasonable attempts must be made to allow the mail server to deliver an e-mail.
There are 3 types of e-mail priorities that are commonly understood: Urgent, Normal and Bulk. The mail client program (e.g. Outlook) will set the priority of the e-mail and this priority will be used to determine what happens to an e-mail if there is some sort of error during transmission.
The remote mail server has two options when there is an error. It can return a permanent error code, something in the range of the numbers from 500 to 599. A permanent error condition (e.g. 550) will result in an immediate return of the e-mail to the sender.
The remote mail server may also return an error code signifying a temporary error either in it's configuration or server state (e.g. the server is too busy to handle the e-mail message). These error codes ranging from 400 to 499 specify the type of error and tell the sending server to try and re-transmit the e-mail after a short delay. Normally this allows for server conditions to change.
Your mail server will try to resend an e-mail with a temporary error for a number of hours. If transmission does not succeed it will send a warning message to the sender, but keep trying to send the e-mail.
After a longer period of time the server will give up on sending the e-mail and return it to the sender with a notification of the delivery failure.
PerfectMail Warning/Return Thresholds:
You can update how long PerfectMail will try to resend e-mails temporary delivery errors. Using the web admin interface, navigate to the MTA Settings page (Server Admin > MTA), click on the "Warning/Return Thresholds" tab, make any required changes and click the "Update" button.
WARNING: Changing Mail Transport Agent (MTA) Settings can have serious implications on the ability of your mail server to handle/deliver e-mail in a timely manner. Modifications to these settings should be made with caution and by administrators with knowledge of how these settings will impact the Mail Transport Agent.
Tags: email, smtp, queue, mail, stuck, delay, warning, return, mta, errors, urgent, bulk, administration
Link to this article: kb/how_long_queue_times
Updated: Monday, August 12, 2013, 13:05
-- David Rutherford