Message contains NUL characters ...

Joseph Brennan brennan at
Thu Apr 28 22:07:33 EDT 2005

It's pretty easy to stop messages with null characters if you use
Mimedefang, a milter.  A built-in function called SuspiciousCharsInBody
tags messages with either nulls or bare CR or LF.  We've let this go
but since we're testing a Cyrus server it looked like we should
stop them coming in.

We started rejecting them about 5 hours ago and it's a remarkably
effective spam filter.  It got about 9,000 so far.  There might be
a legit message in there but I can't see one, just eyeballing the
subject lines.  It gets a lot of Chinese porn spam, and also pirate
software, Viagra ads, bank phishing, etc.  I cannot tell how many had
nulls and how many had bare CR and LF so this might be tangential
to the null discussion.  But certainly legit mail with nulls appears
to be very rare.

Joseph Brennan
Academic Information Systems
Columbia University in the City of New York

Cyrus Home Page:
Cyrus Wiki/FAQ:
List Archives/Info:

More information about the Info-cyrus mailing list