[SLUG] Sendmail Check for forged From headers

[Nigel Allen <dna@xxxxxxxxxxx>]

Hi All

Can anyone point me to a How-To or any other documentation to explain
how to implement the above?

In simple terms, what I want to do for the domain mydomain.com is to
check incoming (external) mail and reject it if it purports to come from
mydomain.com.

I suppose the alternative is to reject incoming mail claiming to be from
mydomain.com that is not being sent from the mailservers of mydomain.com.

Hope this makes sense.

Thanks and Rgds

Nigel.