I have an exchange server that seems to have an issue with one domain receiving emails from my client.
I have seen a delivery delayed message once in the queue.
I have sent test mail to the far end watched the queue as the mail went in and out, however the far end tells me they did not receive the mail.
I have checked blacklists and ensured we are not blacklisted as far as I can tell, as well exchange was originally set up to not allow relaying from day one. I also have the box checked for not allowing blank senders checked.
The interesting part of this, if the user uses reply in outlook the mail does not go, however if the user copies and pastes the email address the mail seems to go through every time.
Any help would be greatly appreciated
Running Exchange 2010 fully updated, Server 2008 R2 Enterprise.