SMTP Connection from outside network will not send, 550 5.7.1 Unable to Relay
Posted on 2006-06-21
Our entire office used to be setup on the same domain and lan. We had no issues this way and everyone's outlook was connected using Exchange as the account type. Now our office has split and half of the people are at a different location on a different domain. I set them up to connect over the WAN to my server and use IMAP/SMTP. Everyone can receive at the new office no problem but when it comes to sending we have issues. We can send to addresses that we host such as email@example.com but cannot send to outside address such as @hotmail.com. For outside address we get the error:
"Your message did not reach some or all of the intended recipients.
Sent: 6/21/2006 12:25 PM
The following recipient(s) could not be reached:
'firstname.lastname@example.org' on 6/21/2006 12:25 PM
550 5.7.1 Unable to relay for email@example.com"
Like i said receiving is fine for the remote office and both sending and receiving work perfectly from the local office where the Exchange 2003 server is hosted from. I know the problem has to do with the Access and security properties of the SMTP Virtual server but am not sure where. I do require the outlook account to authenticate for outgoing mail but am not certain I am typing in the correct login name (ie "mydomain\username" or "firstname.lastname@example.org"). Lastly I should mention that if I add the IP address of the remote client trying to send via SMTP to the relay restrictions area they are able to send, but I dont want to have to add every IP for every client whenever they want to send. Any help is much appreciated!!!!