If all of my users are connecting directly to my exchange server to get there emails and send emails back and forth to one another, why would I need to allow incoming email from someone in my Domain.  I would think that these would be spoofed addresses and bad to begin with.

So I come back to the question, how could I block emails that are showing a from my domain (@domain.com) but not affect the one going to my domain.  Example

Roberto:

I enabled the option "Reject if From Domain = To Domain"  This did not change anything.  The spam filter is still allowing emails that are saying they are coming from my domain when they can't be.  Any ideas, could it be because I have my domain set up in the local domain list thatit will bypass this rule?

ssullivan,

I'm afraid we're confused. Your first post asked "why would I need to allow incoming email from someone in my Domain". The following question is "how could I block emails that are showing a from my domain", and form the last it appears you added your domain to the domain whitelist.

If you can please let us know more specificaly what the issue(s) are, we can help better.

In the meantime, I'll take a stab at interpreting the three questions.

SpamFilter will only accept and deliver emails to the domains you own. These domains must be added to the "Local Domains" in SpamFilter. Only if an email is addressed to a domain in this list it will be accepted for delivery, pending it passes all the other filtering rules. This is not a whitelist, it simply tells SpamFilter that these domains belong to you, and SpamFilter can start examining receiving the email to then check it for spam. If an email arrives that is not addressed to these domains, it will be immediately rejected.

Often spammers will fake their address by using your domain in the "From" of an email. If you enable the "Reject if From Domain = To Domain" option, or better yet, implement SPF in your DNS, these emails will be blocked.

If you add your own domain in the "Whitelisted Domains" whitelist - which note is different than the "Local Domains", then you are effectively whitelisting any incoming email to your domain which has as a sender an address belonging to your domain. Thus all the spam which fake your domain as the sender will bypass all filtering rules.