Right this is my first post here so forgive me if i act all dumb'n'stuff!
Oaky - so we have an exchange server (2003 with SP3) running on our SBS 2003 server (yep i know its rubbish!).
and we seem to have two or three guys who are unable to email any of the guys in our company, they will allways receive an NDR stating that;
Subject: Test Email to Training user
Sent: Tue, 31 Oct 2006 13:10:33 -0000
did not reach the following recipient(s):
*******@My-Company.com on Tue, 31 Oct 2006 13:10:36 -0000
The e-mail account does not exist at the organization this message was sent to. Check the e-mail address, or contact the recipient directly to find out the correct address.
I currently know of three people who are unable to send to our organisation, from what I can gather all of them seem to be sending via a BT connections (heasxxuker.he.local). I have checked our Servers MX records, We have an RDNS entry setup, were not listed on any Spam lists, and ive checked my IMF on my excahnge server, i do now have Symantec Mail Security for Microsoft Exchange setup since last Friday but this problem has been prsent for months.
I'm pretty stuck now as all the posts that i have seen relate to this issue beeing spam and spoofing, this are legitimate emails that were trying to receive, also I have checked MS and Google. No luck!
Any help would be much appreciated.