On 11/6/2012 12:08 AM, David Rees wrote:
On Sun, Nov 4, 2012 at 6:45 PM, Brian Schang <post...@lists.schang.net> wrote:
In the past week, my server has accepted dozens of emails that were not
deliverable. In all cases the issue has been a mail forwarding loop
which resulted in the email bouncing. Given that my configuration has
not changed in many months, I was puzzled. However, a little research
led me to look into a Delivered-To exploit. I looked at a few of the
messages in the queue (postcat), and sure enough those messages had a
Delivered-To header line.
FWIW, I've been seeing the same thing here. First one I saw was on Oct
23, but seems to be increasing in frequency.
Any suggestions on how to handle this in postfix? We're starting to see
this with some frequency as well.
The only solution that I've stumbled across in my web searches is
documented at:
http://forum.spamcop.net/forums/index.php?showtopic=10734
They suggest a "header_checks" of type "pcre" with the following content
in the file:
/^Delivered-To: .*/
REJECT Header Exploit
But this apparently will also break "forward as attachment" mails unless
you change something else (and it's not exactly clear, just that
"nested_header_checks" is involved).
