>>> That policy is rather likely to land you on a blacklist yourself.
>>
>> How will using gmail/yahoo land you on a blacklist?
>
> The thinking of blocking even the postmaster address thinking "they can
use gmail/yahoo", akin to "let them eat cake", that's of issue.
>
> If your system does not accept mail to the postmaster address, you culd be
listed on some RBLs... like this one:
http://www.rfc-ignorant.org/
The RFC clearly states that your should name the postmaster address
world-acceptable *OR* give an alternative email address insead. I think it
is okay to let your blocked users contact you on your gmail addy instead..
:P
My mail server at my pc tells you to mail to
blacklist-{DailyRandomCode}@{domain.dom}...
I would simply look at the dns record, domain record and website instead...
:)