If you do not have very many domains, this is easily handled by looking at it in reverse,  Do not try to block INVALID addresses with the black lists; ... rather allow VALID address with the "authorized to addresses" list.  I have not tried this because I nnhave over 200 domains and none of them follow any nice pattern at all but I am fairly sure this RegEx will do the trick.

For example:

((.){1,}[\.](.){1,}(\@domain.com))

will match anychar(s) followed by a "dot" followed by anychar(s) followed by "@domain.com)

I hope this helps you.

Regards,

Dan S. 

Christopher,

Just so long as you don't think I am some sort of RegEx expert.  I do OK but often get stuck trying to do something that SHOULD be simple. This is using Delphi's (I believe) RegEx "Engine" and I am more used to Perl.  Close but get's me into trouble sometimes!

Dan S.

Message to Dan,

I know you wish not to be called the expert, but I must agree, your Sample RegEx keyword list does wonders. I had mentioned before That I would be glad to host out the file, to prevent any abuse you may recieved, we have a dedicated connection that is not in use for anything here, in fact, I used to run an unofficial forum to help create the blacklist files, It wasnt used much, but did help for a while. Let me know if you would want to put together something to help the others out. At the same time it may help us as well. I have a quite simple way to dish out a running blacklist to users, and since the files arent too big the bandwidth is no big deal, plus I'm not using the connect for anything else.

Let me know.

If anyone else would like to suggest, or help out, also let me know.

Sean