This seems to be a common question, but I still seem to be having issues.
Your message did not reach some or all of the intended recipients.
Subject: Origianl Subject
Sent: Date Time
The following recipient(s) could not be reached:
'Recipient Mail Address' on Date Time
You do not have permission to send to this recipient. For assistance, contact your system administrator.
<Mail server FQDN #5.7.1 smtp;550 5.7.1 Unable to relay for Recipient Mail Address <mailto:Recipient Mail Address>>
I have a SBS2003 Server with Exchange 2003 running where all inhouse email and most outside email goes through without incident. I am however running into an issue where the above error is coming back to us on, at this time, only one address.
I have checked for the possibility of being on a RBL list and I'm not listed. I have checked the relay for authenticated machines and it is active. I have also looked at responses about the Reverse PTR and I have my internal IP and external IP listed.
Any further thoughts would be greatly appreciated.