Hello at all Plesk Warden Anti-spam and Virus Protection users,
at the moment we are facing an outgoing spam problem caused by not blocking detected spam messages if mail was sent to an email alias address.
Steps to reproduce:
-> create an email address e.g.:
mail@domain.com
-> create an email alias for the mailbox e.g.:
alias@domain.com
-> switch on mail forwarding to e.g.:
forward@second-domain.com
-> set spam action for the mailbox to "block" (for testing purpose maybe set spam level to -9)
If an email is sent to "
mail@domain.com" and it is detected as spam all works fine:
-> delivery is rejected (milter-reject) and forwarding is not triggered
BUT if an email is sent to the alias address
alias@domain.com the following happens:
-> message is still detected as SPAM
-> but it is not blocked, it is sent via postfix/pipe to the main address
mail@domain.com
-> an then it is forwarded to the forward email address (outbound spam detected again!)
-> the provider on the other side then step by step blocks us as spammers
I know external forwarding is never a good solution, but we still need it in some cases. And the block solution would be ok for us because we set a low sensitivity. We are just wondering, why the alias email addresses of the mailbox can bypass the block rule that is working fine on the main email address of the mailbox.
Our only work-around right now is to not use alias addresses and create own mailboxes for every alias with a forwarding. But some clients will not understand / accept.
Any help or hint how to reconfigure the mail server to honor the block rule also for aliases is very appreciated. Thanks in advance!