[Mimedefang] Verizon and greylisting

[David F. Skoll]

Joseph Brennan wrote:
> Jeff Rife <mimedefang at nabs.net> wrote:
>> if ($Sender eq '<>')        # don't greylist here for DSN or callback
>>   {
>>   if ($#Recipients > 1)     # Can't have more than one with null sender

> This is false.

It is false in general, but if you have complete knowledge of all
the types of mail sent from your domain, it may be true.  For example,
I know for a fact that there's no reason for a DSN to be sent to
more than one roaringpenguin.com address.

I agree that for a university, this assumption is likely to be invalid.

Regards,

David.