Sendmail:How to relay when user logs in remotely from any IP with valid user/pass
I have the Sendmail/Dovecot mail server up and running fine. I am worried about spammers using my server for relaying now. I have it set to relay from anywhere in my LAN, or the localhost, or the domain, however if someone tries to sendmail through my server using IP addresses common to LANs it will send. Or if I send remotely from another IP it won't even with a valid user/pass. So my question is how to I relay only for those who login with a valid user or pass via a database that logs IP's then timesout that IP eventually from users that login to sendmail?