[Mimedefang] Rejecting e-mails with blank CC: and Reply-To:

[Michal.Jankowski at fuw.edu.pl]

> Hello,
>
> We receive messages from a system that sends e-mails with a blank
> Reply-To: and CC: lines, and (I think) mimedefang is rejecting them.
>
> This is what I see logged on my system:
>
> Apr 10 08:04:57 mx sendmail[1400]: q3AF4uDC001400: collect: premature EOM:
> unexpected close

> And this is what our upstream mail handler gets:
>
> (hostXXXX.thermeon.com[1.2.3.4] said: 554 5.7.1 This message has been
> blocked because the return email domain is invalid.(domain name   has
> invalid syntax) (in reply to end of DATA command))

This looks like a cisco router/firewall/asa/whatever intercepting
smtp traffic and doing own 'fixups'. Switch it off.

http://blogs.oucs.ox.ac.uk/networks/2009/11/26/cisco-firewall-smtp-fixup-considered-harmful/

http://www.binarywar.com/2009/11/cisco-pixasa-causes-smtp-banner-corruption/

  MJ