Description
Solution
When bounce verification is enabled some Out of Office messages are marked as bounce verification failed.
Solution
This behavior is correct.
The cause of this is that some mail servers do not use the sender's email address from SMTP envelope but use the sender's address from mail headers to deliver OoO.
The problem is that the email address in mail headers does not contain bounce verification tag, hence FortiMail does not have any opportunity to recognize this message correctly (and is marking it as bounce verification fail).
For example:
As a workaround, Bounce verification exempts can be created in 'AntiSpam > Bounce Verification > Tagging Exempt List or Verification Exempt List' for domains or hosts that are having the problem.
The cause of this is that some mail servers do not use the sender's email address from SMTP envelope but use the sender's address from mail headers to deliver OoO.
The problem is that the email address in mail headers does not contain bounce verification tag, hence FortiMail does not have any opportunity to recognize this message correctly (and is marking it as bounce verification fail).
For example:
CorrectThe OoO message should use 'prvs=<keyvalue>=sender@domain.tld' in RCPT TO, the problem is when 'sender@domain.tld' is used instead.
MAIL FROM:<>
RCPT TO:<prvs=<keyvalue>=sender@domain.tld>
Incorrect
MAIL FROM:<>
RCPT TO:<sender@domain.tld>
As a workaround, Bounce verification exempts can be created in 'AntiSpam > Bounce Verification > Tagging Exempt List or Verification Exempt List' for domains or hosts that are having the problem.
- For more information on Tagging Exempt List refer to the 'Excluding recipient domains from bounce verification' section of the FortiMail Online Help guide.
- For more information on the Verification Exempt List refer to the 'Excluding senders from bounce verification' section of the FortiMail Online Help guide.
- For more information refer to the 'Configuring sender validation options' and 'Configuring advanced scan settings' sections of the FortiMail Online Help Guide.
