I am having sporadic issues with my Exchange 2003 mail server running on Windows SBS 2003. Every so often I will get an email from one of our clients that has the domain of zahav.net.il, which is based in Israel and I am based in the US, and they state that they received a non delivery report when sending to my domain with error code 4.4.7.
This is only sporadic, and sometimes I do indeed receive emails from them, and other times not. I am running Exchange 2003 version 6.5 SP2. This is really one of the only domains I seem to be experiencing issues when receiving. I have gone through my local mail queues and cannot find a single instance of the failed message. It's like it doesn't even hit my Exchange server. At first I was thinking that this is an issue with their mail server, but I have been made aware that the 4.4.7 errors seem to be related to the "receiving" server and not the "sending" server. I have checked to make sure my domain is not blacklisted, which it is not, and I also have the correct PTR record set on my domain.
Any help with this is greatly appreciated as I am at a stand still on what to test and troubleshoot any further. Thank you.