Relaying with sendmail 8.11

[Lora Ganeva]

I have a problem with my mail relay:if anyone pretends to be from a local domain, he could send mail to my local domains:
for example:
mail from: kjkjk@btc.bg
rcpt to: jhjhj@btc.bg
Message is accepted although the sender is not actually in btc.domain but only pretends to be.

[David Rodman]

In my feable knowledge, there is no way for sendmail to validate a sender address from a remote domain. Sendmail is faithfully delivering mail as it should to your local users, so this is not a "relay" problem.

You may want to look at a firewall with an email proxy that will screen or authenticate smtp connections.