Mailing List Archive

Lots of qmail recieved headers causing sendmail to barf....
Here's a real-world situation where the use of qmail (as I configured it)
caused a problem.

This legitmate message got bounced because sendmail at another site thought it
must be in a loop. I know you could consider this a sendmail problem (since
it really is), but the fact is that this wasn't a problem before.

Anyway, what happened here is that a user named spletter sent a message from exm
h on a host named "sage" to "users-group@savantage.com".

Exmh is built on mh and therefore uses smtp to get the message into the mail
system. That's two headers.

Sage is not the mailhost, so the message got sent to the mailhost to be
processed. That's two more headers giving us four.

The users-group mailing is is actually managed by spletter, so it gets forwarded
to spletter-users-group@savantage.com. We're up to five headers.

Spletter's home directory is on sage. I had done as advised here and in the
FAQ and caused mail to him and his lists to be forwarded to the system his
account is on instead of using NFS. Two more headers, giving us seven.

The list expands. Most list members are directly on this list, but the staff
of savantage is all included via a sublist of "all@savantage.com". So, a copy
of this is sent there...back to the mailhost. Three more headers. We're up
to 10.

"all@savantage.com" is made up of organizational lists including
"marketing@savantage.com". 11 headers.

One of these people is gunnar, (4 more headers) who is actually located in
Sweden so it gets sent to the firewall (oregano.savantage.com) (3 headers to
do that). We've got 18 headers before leaving qmail-land.

The firewall then forwards the message to a sendmail host who adds one more
header before sending it on to another sendmail host who bounces it. 20
received headers all together.

Do I ask the postmaster in sweden to raise this limit with a strong hint that
he too should be using qmail? What do I do in the meantime? Can I limit a
few of these hops? I can (and should) move gunnar's account to the mailhost
itself. That will save a few, but...

...while typing all that a second bounce came in (also appended), this time
from AOL. Do I try to convince AOL to run qmail also?

Chris
Re: Lots of qmail recieved headers causing sendmail to barf.... [ In reply to ]
>...
> The firewall then forwards the message to a sendmail host who adds one more
> header before sending it on to another sendmail host who bounces it. 20
> received headers all together.

Strictly speaking, this is neither a sendmail problem nor a qmail
problem. It is a configuration problem of the world-wide mailing
network seen as a whole, which gets worse by qmail's many Received
lines.

There will always be situations where you run into this problem and I
can't see a better solution than was already done with the IP TTL:
up the limit. :-/

A quick hack would be to patch the call to received_setup() out of
qmail-queue.c, but don't tell anybody I said that :-)

olaf