The esteemed Bruce Harrison has said:

Installing a new version of mailman on a new virtual machine (debian 4.6.3-14), and Mailman is complaining of a group mismatch error on the mail-wrapper. System is executing as mail and mailman wants it executed as mailman group.

Looked for the smrsh config in sendmail, but this version on Debian seems not to use that. Also can't get sendmail to accept remote connections. Localhost works fine. Telnet to port 25 on host works fine. Remote telnet gets "554 mailman2.xxx.xxx ESMTP not accepting messages

Looked at various pages on the web for sendmail and mailman, but not finding much.

I'm convinced it's a setting in sendmail,but... no idea what it is.

Any sendmail experts out there?

I'll respond to this because I don't see any other responses on the Mailman mail list, and I use sendmail with Mailman on a Solaris 10 system. I've used sendmail ever since there was a sendmail, but would hardly call myself an "expert." I use sendmail because the Solaris distributions have a good implementation as a part of the general distribution.

First off, let me say that MTA's in general are supported using MTA-specific resources.

Also, and more importantly, you have to have whatever MTA you are using already set up to send and receive mail from MUA clients before thinking about integrating Mailman as an additional MUA. I don't know what's available for sendmail on Debian, what the quality of any prepackaged distribution is (or isn't). I do know that smrsh is part of the sendmail package, so if you don't have it somewhere on your system, you probably haven't got a good sendmail to work with. In that case. It's open source, so you can compile your own, which I'd recommend unless you've got a known-good distribution available.

For sendmail support, the distribution website has a lot of information, and there is a big README included in the package. Most administrators who do sendmail have a copy of the O'Reilly "Sendmail" book, commonly called the "Bat Book." You'll need that. There is also a comp.mail/sendmail Usenet group, which is reasonably active.

If you are limited to prepackaged distributions, I'd strongly suggest using Postfix on a Debian system.

Hank