Monitoring the system : Managing the deferred mail queue
Managing the deferred mail queue
The FortiMail unit prioritizes the mail queue into two types:
• Regular mail queue
When the initial attempt to deliver an email fails, the FortiMail unit moves the email to the regular mail queue.
• Slow mail queue
After another two failed delivery attempts, the FortiMail unit moves the email to the slow mail queue. This allows the FortiMail unit to resend valid email quickly, instead of keep resending invalid email (for example, email destined to an invalid MTA).
 
After the undelivered email remains in the deferred queue for five minutes, the mail appears under Monitor > Mail Queue > Mail Queue. This also means that email staying in the deferred queue for less than five minutes does not appear on the Mail Queue tab.
Delivery failure can be caused by temporary reasons such as interruptions to network connectivity. FortiMail units will periodically retry delivery. (Administrators can also manually initiate a retry.) If the email is subsequently sent successfully, the FortiMail unit simply removes the email from the queue. It does not notify the sender. But if delivery continues to be deferred, the FortiMail unit eventually sends an initial delivery status notification (DSN) email message to notify the sender that delivery has not yet succeeded. Finally, if the FortiMail unit cannot send the email message by the end of the time limit for delivery retries, the FortiMail unit sends a final DSN to notify the sender about the delivery failure and deletes the email message from the deferred queue. If the sender cannot receive this notification, such as if the sender’s SMTP server is unreachable or if the sender address is invalid or empty, the FortiMail unit will save a copy of the email in the dead mail folder. For more information, see “Managing undeliverable mail”.
For information on configuring the delivery retry interval, maximum amount of time that an email message can spend in a queue, and DSN timing, see “Configuring mail server settings”.
When you delete a deferred email, the FortiMail unit sends an email message, with the deleted email attached to it, to notify the sender.
To access this part of the web UI, your administrator account’s:
• Domain must be System
• access profile must have Read-Write permission to the Policy category
For details, see “About administrator account permissions and domains”.
To view, delete, or resend an email in the deferred mail queue, go to Monitor > Mail Queue > Mail Queue.
 
To reduce the amount of hard disk space consumed by quarantined mail, regularly release or delete the contents of each recipient’s quarantine.
 
Table 3: Managing the deferred mail queue
GUI item
Description
View (button)
Select a message and click View to see its contents.
Delete (button)
Click to deleted the selected item.
Resend
(button)
Mark the check boxes of the rows corresponding to the email messages that you want to immediately retry to send, then click Resend.
To determine if these retries succeeded, click Refresh. If a retry succeeds, the email will no longer appear in either the deferred mail queue or the dead mail folder. Otherwise, the retry has failed.
Type
Select the directionality and priority level of email to filter the mail queue display. For details about email directionality, see “Incoming versus outgoing email messages”.
• Default: Displays all email in the regular mail queue.
• Incoming: Only displays the incoming email in the regular mail queue.
• Outgoing: Only displays the outgoing email in the regular mail queue.
• IBE: Only displays the IBE email in the regular mail queue. For information about IBE email, see “Configuring IBE encryption”.
• Default-slow: Displays all email in the slow mail queue.
• Incoming-slow: Displays the incoming email in the slow mail queue.
• Outgoing-slow: Displays the outgoing email in the slow mail queue.
• IBE-slow: Displays the IBE email in the slow mail queue.
Search
(button)
Select to filter the mail queue display by entering criteria that email must match in order to be visible.
Session ID
Lists the Session-Id: message header of the email.
Envelope From
Lists the sender (MAIL FROM:) of the email.
Envelope To
Lists the recipient (RCPT TO:) of the email.
Subject
Lists the email subjects.
Reason
Lists the reasons why the email has been deferred, such as DNS lookup failure or refused connections.
First Processed
Lists the date and time that the FortiMail unit first tried to send the email.
Last Processed
Lists the date and time that the FortiMail unit last tried to send the email.
Tries
Lists the number of times that the FortiMail unit has tried to send the email.