[Cialug] Sendmail spam rejection

[Aaron Porter]

On 10/24/06, Daniel A. Ramaley <daniel.ramaley at drake.edu> wrote:
> I have what is hopefully an easy question for the sendmail wizards on
> this list. I have 2 mail servers. The first receives mail from the
> outside world, filters out most of the spam, and then passes the mail
> to the second server (which is what users actually log in to to check
> their mail). The first server runs sendmail. It does not currently have
> a way to verify the recipient addresses, so it just accepts all mail
> for the domain. Then when the first server forwards mail on to the
> second server, any invalid recipients cause a bounce to be generated.

Hmmm... a little googling later: might milter-ahead work for you?

http://www.snertsoft.com/sendmail/milter-ahead/