Recently a user has reported a problem emailing an external contact they get a NDR back saying :
Your message did not reach some or all of the intended recipients.
Sent: 28/09/2007 10:27
The following recipient(s) could not be reached:
exampleuser@external..Gov.UK on 28/09/2007 10:27
You do not have permission to send to this recipient. For assistance, contact your system administrator.
<hda02.hf.external.gov.uk #5.7.1> <- Not ANY of our exchange servers
When I trace the message via Exchange the email is passed out of exchange and onto our hosting email servers (MessageLabs)
"Message Transferred to server-4.tower.messagelabs.com through SMTP'
from further investigating it turns out no one can email this external address they get the same NDR. However I can email the address from my Hotmail account. As the message leaves exchange and passes to our hosting mail servers is this a problem with my end...or the External users ?