Sorry my server died on me. Got the following error:
(98)Address already in use: make_sock: could not bind to address [::]:80
no listening sockets available, shutting down
Unable to open logs
I tried everything apt-get purge... reinstalling and nothing so I am going to format and install from scratch. I had in in my mind to do it at some point but I guess now is as good a time as any.
As for the mail server name I think it's best to use the hostname (FQDN) of the server but this raises an issue if your server (via perl) sends an email to clients.
I will need to look into this after the server is back up.