sendmail query

[padraig]

we use sendmail as our external mailhubs & relay to zimbra

just a quick question on /etc/mail/access is it possible to reject a domain unless its from a specific server/relay

e.g. /etc/mail/access

From:somedomain.com REJECT unless from source blah

[uxbod]

According to Controlling SMTP Relaying - Tips - sendmail.org then no it is not possible. If you had another instance of SendMail running on another port then you could be selective on your firewall as to what hosts could connect to it. You could then switch of any spam checking. Alternatively setup TLS and start using signatures.