[Mailman-Users] sendmail and mm-handler woes

Kevin McNamee kevin.mcnamee at symsoft.se
Mon Feb 13 11:32:09 CET 2006

Hi Mark,

Ok found the problem. The short story is that I had defined a CNAME and not
a proper sub domain for mailman. When I fixed this then sendmail could
correctly use the mailertable. Analysis below.

I now have a different problem which is more in the Mailman realm. When I
try to post messages to a list they do not appear in the archives and the
mail is not sent out to members. I have tested with the following:

> su - mailman
> echo "testing" | "/usr/local/mailman/mail/mailman" post testlist

This message ends up in the moderator queue. I accept the message but it
does not appear in the archives and neither is the mail sent to members.
Nothing useful appears in the /usr/local/mailman/logs files. 
Any ideas?

"User unknown" analysis
If the "user unknown" problem arises, then sendmail is not 
recognising your domain as a "mailman" domain. 
The problem could be that your mailman.mydomain.com is defined as a 
CNAME not a real DNS record. 

A hint from a tutorial about Masquerading:
"This address must be an address record in DNS, not simply
a CNAME, or the remote end will canonicalize the address back 
to the original name."

First confirm the problem
# sendmail -bv testlist<at>mailman.mydomain.com
testlist<at>mailman.mydomain.com... User unknown

Then confirm that mailertable is operational
# sendmail -d -bv jbloggs<at>hotmail.com | egrep "map_rewrite|mailertable"
map_lookup(host, hotmail.com) => host_map_lookup(hotmail.com) =>
map_rewrite(hotmail.com), av =
map_rewrite => hotmail.com.
map_lookup(mailertable, hotmail.com) => NOT FOUND (0)
map_lookup(mailertable, .com) => NOT FOUND (0)
map_lookup(mailertable, .) => NOT FOUND (0)

Then confirm that your domain (CNAME) is being canonicalised:
# sendmail -d -bv testlist<at>mailman.mydomain.com | egrep
map_lookup(host, mailman.mydomain.com) =>
host_map_lookup(mailman.mydomain.com) => map_rewrite(aserver.mydomain.com),
av =
map_rewrite => aserver.mydomain.com.

Sendmail has done an nslookup and found the real name of your domain which
would not match your settings in mailertable (if sendmail got that far).

If you remove the CNAME and create a real subdomain, then the problem will
go away:
# sendmail -bv testlist<at>mailman.mydomain.com
testlist<at>mailman.mydomain.com... deliverable: mailer mailman, host
testlist<at>mailman.mydomain.com, user testlist

You will still need to create a new CNAME in your sub-domain for Apache to

It is very important to make clear in the Mailman installation instructions
that a REAL subdomain is needed. Those of us not familiar with DNS (or
sendmail for that matter) can succeed in getting the whole Mailman
installation working including the (Apache) web-interface and subscription
management using just a CNAME and then wonder why we cannot send mail to our
list. Hope this is of use.


-----Original Message-----
From: Mark Sapiro [mailto:msapiro at value.net] 
Sent: 12 February 2006 16:57
To: Kevin McNamee; mailman-users at python.org
Subject: Re: [Mailman-Users] sendmail and mm-handler woes

Kevin McNamee wrote:
>Yep, I have created my mailertable map also. I am no sendmail expert either
>but I am being forced to look closely at how it is set up. Found a useful
>tutorial here (there are many more): http://www.feep.net/sendmail/tutorial/

When you get this worked out, if you find that the mm-handler.readme is
unclear or needs improvement, please pass along your suggestions so
they can be incorporated in the readme and/or a FAQ.

Mark Sapiro <msapiro at value.net>       The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

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