[vox-tech] spam current events

[Rick Moen]

Quoting Ryan (cjg5ehir02 at sneakemail.com):

> Exim can do this, and calls it callout verification.  It's not really advised 
> for use, though, and some email providers will blacklist you for using it 
> (AOL, probably others)

Er, my Exim4 setup does callout verification on all incoming mail, and
neither AOL nor to my knowledge anyone else has blacklisted my IP.

In fact, my setup verifies not only that claimed sender address is
deliverable before 250-Accept, but also verifies via callout that
claimed sending domain has postmaster and abuse accounts, and accepts
mail from the null sender, all of those being RFC requirements.