Select the maximum number of hours that deferred email messages can remain in the deferred or quarantined email queue, during which the FortiMail unit periodically retries to send the message.

After it reaches the maximum time, the FortiMail unit sends a final delivery status notification (DSN) email message to notify the sender that the email message was undeliverable.

Select the maximum number of hours a delivery status notification (DSN) message can remain in the mail queues. After it reaches the maximum, the FortiMail unit moves the DSN email to the dead mail folder.

If set to zero (0), the FortiMail unit attempts to deliver the DSN only once.

Select the number of hours after an initial failure to deliver an email message before the FortiMail unit sends the first delivery status notification (DSN) message to notify the sender that the email message was deferred.

After sending this initial DSN, the FortiMail unit continues trying to sending the email until reaching the limit configured in <GUIElement>Maximum time for email in queue.

Select the number of minutes between delivery retries for email messages in the deferred and spam mail queues.

Enter the number of days that undeliverable email and its associated DSN will be kept in the dead mail folder. After this time, the dead email and its DSN are automatically deleted.

Mark the check box to disable (ESMTP) for outgoing email.

By default, FortiMail units can use ESMTP commands. ESMTP supports email messages with graphics, sound, video, and text in various languages. For more information on ESMTP, see RFC 1869.