We have a remote user who is using IMAP for collecting mail from our exchange 2013 server. When sending mail internally to our domain it is coming through correctly, but when he tried to send to an external domain he get the message below;
Your message did not reach some or all of the intended recipients.
Subject: Quote for Wolf Castle Hotel
Sent: 15/10/2013 16:22
The following recipient(s) cannot be reached:
'email@example.com' on 15/10/2013 16:22
550 5.7.1 Unable to relay
Is this just a missed setting somewhere in exchange 2013?
Thanks in advance