Mail Queue

Mail Queue ~~Management~~ enables you to manage the SMTP email server queue. In this page, you can adjust the the Bounce and Max Queue Lifetime settings as well as Flush Mail Queue, View, Requeue, Hold or Delete messages from the queue.

Normally, the Mail Queue should be empty, since the SMTP server should deliver the email as soon as they arrive in the queue. If messages arrive and stay undelivered in the queue for long periods of time, that usually indicates a problem with either the local system or the remote receiving system.

Bounce Queue Lifetime and Max Queue Lifetime

The Bounce Queue Lifetime determine how long a MAILER-DAEMON messages stays in the queue before it's considered undeliverable. This setting stricly controls non-delivery messages generated by the SMTP server. Once the lifetime expires the MAILER-DAEMON messages are automatically removed from the queue by the system. The default is 5 Days. If this is set to 0 Days, delivery will be tried only once and then removed from the queue.

The Max Queue Lifetime determines how long all other messages stay in the queue before the SMTP server considers them undeliverable and sends a bounce message back to the sender. This setting controls how long the system will hold on and try to relay messages to other mail servers. Ideally, this setting should be set high enough so that the system holds on to messages as long as possible before bouncing them. This is especially important if you are relaying messages to external email servers that may go down for long periods of time. The default is 14 days. If this is set to 0 days, delivery will be tried only once and then a bounce message will be sent to the sender (Not recommended).

Select the Bounce Queue Lifetime setting you wish from the drop-down.
Select the Max Queue Lifetime setting you wish from the drop-down.
Click the ~~Set~~Submit button (Figure 1).

Figure 1

The Mail Queue

Email is listed in the queue with the following fields (Figure 2):

Message ID - Internal system assigned ID for the message
On Hold - Indicates whether or not the message has been put On Hold
Date - Date of the message
From - The From field of the message
To - The To field of the message
Subject - the Subject of the message
Diagnostic Code - The SMTP error code generated for the message
View Message - Enables you to view the details of the message

Figure 2

Reload Mail Queue

The Mail Queue Management page does not auto-refresh. Click the Reload Mail Queue button to reload the mail queue listing (Figure 3).

Figure 3

Requeue Messages

When you re-queue messages, you are forcing the SMTP server to try delivery immediately instead of waiting for the next interval.

Place a checkmark under the Select column of the message(s) you wish to requeue and click the Requeue Msg button (Figure 4).

Figure 4

Hold Messages

When you hold messages, you are forcing the SMTP server to hold delivery of those messages. The messages will be On Hold until those messages are Requeued again.

Place a checkmark under the Select column of the message(s) you wish to hold and click the Hold Msg button (Figure 5).

Figure 5

The system will place the selected messages On Hold (Figure 6). Note, that sometimes you may have to repeat the process for the message to be put On Hold.

Figure 6

Delete Messages

When you delete messages, you are forcing the SMTP server to immediately remove those messages from the mail queue.

Note that deleting messages from the queue should be carefully considered. If users were expecting those emails to be delivered, removing them from the queue will quarantee that they will never get delivered.

Place a checkmark under the Select column of the message(s) you wish to requeue and click the Delete Msg button (Figure 7).

Figure 7

View Messages

Viewing a message reveals very detailed information about the message which can assist in determining why the message is stuck in the mail queue.

Click on the icon under the View Message column of the message you wish to view (Figure 8).

Figure 8

You will be directed to the View Queue Message page where you will be able to view all the detailed information about the message as well as the message itself (Figure 9).

Figure 9