As I'd been having other problems (now resolved) I tried to run the update script with a fresh download of 188.8.131.52. Unfortunately Mailman is now misbehaving. Initially Mailman threw up the following in mail.warn: May 13 22:44:04 ***** postfix/cleanup: warning: database /var/ lib/mailman/data/virtual-mailman.db is older than source file /var/l ib/mailman/data/virtual-mailman I've fixed this with postmap /var/lib/mailman/data/virtual-aliases Now I receive an error when trying to post to a list that shows in mail.log as: May 13 23:12:58 ***** postfix/smtpd: NOQUEUE: reject: RCPT fr om **.myisp.tld[**.**.**.**]: 550 5.1.1 <firstname.lastname@example.org>: Recipient address rejected: User unknown in virtual mailbox table; from=<email@example.com> to=<firstname.lastname@example.org> proto=ESMTP helo=<[10.0.1.16]> Searching on the forums I saw the 184.108.40.206 issue but my /etc/mailman/virtual_to_transport is correct. Any ideas?