Eric Shubert wrote:
On 01/03/2011 04:34 PM, Brent Gardner wrote:
Been doing more research, looks like the "Header line length limited
only by memory" thing only applies to qmail-inject
(http://cr.yp.to/qmail.html).
I think qmail's only accepting headers of up to 998 characters unfolded
length. RFC 2822 and 5322 both mention this number as the max length for
a single line in a message. The "References:" header is displayed as a
multi-line entity, but when you 'unfold' it, or remove the CRLF at the
end of each line so it's one line, it can only be up to 998 characters.
I've tested this using blat as well as a vbscript that uses Microsoft's
CDO.Message. If I try to send a message with a "References:" header of
998 characters it goes through. If I try with 999 characters, qmail
drops the connection without any kind of log entry or message to the
remote machine such as 'malformed header'.
A log message would indeed seem appropriate.
Of course, if I send messages directly to my Exchange server via port
25, the messages go through.
Now I'm a position where I have to tell our clients that Microsoft's
SMTP implementation is not compliant, or I have to find a way to get
qmail to relax its standards.
Has anyone else run into this?
I haven't, but I haven't had much contact with Exchange.
It seems to me that it'd be fairly simple to patch qmail-smtp to allow
for longer lines. This would of course use a little more ram for each
smtp session, but that's probably livable.
Whether such a change is appropriate or not is debatable. While it is
certainly not compliant, it doesn't break other things, and allows QMT
to be more compatible with Exchange. So my take is that it would be a
good thing.
If you need some help with this, feel free to contact me off list.
Nice work Brent.
So it turns out that my problem was ESMTP filtering in our Cisco ASA. I
turned it off and my test messages went right through. Argh. That was
the first thing I checked when I started working this issue, but I just
glanced at it. Darned Cisco GUI interface doesn't seem to show the
details of default filters. I found it after checking via command-line.
Brent Gardner
---------------------------------------------------------------------------------
Qmailtoaster is sponsored by Vickers Consulting Group
(www.vickersconsulting.com)
Vickers Consulting Group offers Qmailtoaster support and installations.
If you need professional help with your setup, contact them today!
---------------------------------------------------------------------------------
Please visit qmailtoaster.com for the latest news, updates, and packages.
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
