Treat Invalid Watermarks with No Sender as Spam

Kevin Miller Kevin_Miller at
Sat Feb 22 01:23:28 GMT 2014

What are your watermark settings in MailScanner.conf?  The idea behind a watermark is outbound mail gets watermarked. Bounces include the original headers so the watermark should be in it if it came from you.  If there's no watermark it implies it's a forged NDR.  (You probably already understand all that - just being pedantic.)
Can you check your outbound messages to verify they're getting watermarked?  Maybe post some examples to pastebin.  It's hard to say w/o seeing the actual message headers.  Post your watermark settings too.  Naturally you'll want to munge the "Watermark Secret" to something other than the actual value you use.
Kevin Miller
Network/email Administrator, CBJ MIS Dept.
155 South Seward Street
Juneau, Alaska 99801
Phone: (907) 586-0242, Fax: (907) 586-4500
Registered Linux User No: 307357
From: mailscanner-bounces at [mailto:mailscanner-bounces at] On Behalf Of Shawn Iverson
Sent: Friday, February 21, 2014 4:03 PM
To: mailscanner at
Subject: Treat Invalid Watermarks with No Sender as Spam

I am having issues where legitimate bounces, out of office messages, delivery receipts, and so forth are being marked as spam due to no watermark or sender address.

Treat Invalid Watermarks with No Sender As Spam = high-scoring spam

It appears that these messages indeed to not have a valid watermark or sender address anywhere, even though they are legitimate incoming emails.

Is this expected behavior?  It appears that many remote servers strip off the original MIME Header...

Shawn Iverson
Rush County Schools
District Technology Coordinator
iversons at<mailto:iversons at>

This message has been scanned for viruses and dangerous content by
E.F.A. Project<>, and is believed to be clean.
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