Receiving empty messages

Hi!
Time to time my system receives totally empty message (not even “to:” or other receiver info) like:

Return-Path: <gwwparicefuc@yahoo.com>
Received: from 119.86.183.125 (119.86.183.125) by webmail.domain.com (Axigen)
 with SMTP id 246686; Mon, 21 Sep 2020 11:05:42 +0300
Message-ID: <1600675543518608675@webmail.domain.com>
X-AXIGEN-DK-Result: No records
DomainKey-Status: no signature
X-AXIGEN-DKIM-Result: No records
DKIM-Status: no signature

Those messages go (of course) to folder “Unknown”.
What messages are these? Spam system testing that if domain is receiving messages at all?!?
Why axigen accepts these messages where there is no receiver information at all?!? Should SMTP protocol prevent these, because sender don’t specify RCPT.

Hello,

By default there is no “Unknown” folder.

I could only guess that you have configured the domain with “Catch-all” that it allows you to receive messages for Emails sent to non-existing users of this domain.

BTW - having no “TO” header into the received message does not means that the sender doesn’t specified the “rcpt to” information into the SMTP-IN session.

My advice is to set the log level to Protocol Communication for SMTP-Receiving and Processing services so you could have a better understanding of how these messages are received and delivered to that folder.

HTH,
Ioan

Thank you!
Yes, that “unknown” was actually translation from Finnish folder name where “Catch-all” puts unknown messages.
I changed log level… Let’s see what we get… :wink: