If you are getting local email (to local users, eg root) bounced back with errors stating ‘mail loops back to self’, ensure that the hostname
and domainname
map to localhost and localdomain respectively:
<code> hostname localhost domainname localdomain </code>
If you set these to be a hostname or domainname that you have for your MX DNS entry, this seems to give the error ‘mail loops back to self’