Originally posted here by ss2chef
Hi what every you do be sure NOT to block null senders at the server level...]
To be more specific...at the listed MX for your domains.

I thinks its RFC 1123 telling you to accept null senders for NDRs and whatnot.

I have seen people get blacklisted for this..

Just an FYI
Thanks for that but I am trying to block them at the client level (I am not a server Admin and I guess from what your saying the ISP can't just block the NULL sender). Is there a a way to do it as a client? Currently, I am using outlook 2k but if I different product supports that I would be tempted to switch. I'll be sure to read 1123.

Cheers,
-D