I have a little issue with all my mailing lists. For every mailinglist there is always one fixed user (in the sample below email@example.com) appearing in all outgoing messages.
We are using Mailman 2.1.2 with Postfix 2.0.14. Here a sample from a mail sent to a different user than in this header:
[...] Received: (qmail 17852 invoked from network); 9 Jun 2005 06:45:29 -0000 Received: from unknown (HELO mailmanserver.somewhere.com) (firstname.lastname@example.org) (envelope-sender email@example.com) by smtp.provider.com (qmail-ldap-1.03) with SMTP for firstname.lastname@example.org; 9 Jun 2005 06:45:29 -0000 Received: from mailmanserver.somewhere.com (localhost [127.0.0.1]) by mailmanserver.somewhere.com (Postfix) with ESMTP id 0C14870BF; Thu, 9 Jun 2005 08:45:29 +0200 (CEST) [...]
Does this look like a mailman, postfix or provider problem?