Problems sending outgoing emails with Exchange 2003
Emails have been working fine up until recently. When a user tries to send an email to a hotmail address it bounces back with the following error....
I have a funny feeling it is my DNS because our DNS has been slow to resolve domains for the past couple of weeks. I thought i had solved this by using our ISP dns servers as the forwarders (instead of OpenDNS.)
Your message did not reach some or all of the intended recipients.
Sent: 31/03/2009 02:09
The following recipient(s) cannot be reached:
*****@hotmail.co.uk on 31/03/2009 02:10
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<server.Allan.local #5.5.0 smtp;550 Requested action not taken: mailbox unavailable>
However, if i do nslookup hotmail.co.uk at command prompt i get the follow response.
So this makes me think that DNS is set up correctly. Our server is set to use itself for DNS in network connections.
C:\Documents and Settings\Administrator>nslookup hotmail.co.uk
This now is happening to all external email addresses.
I have tried creating a SMTP connector and then forwarding mail to my ISP's mail server but this made no difference (Maybe I didn't set up the connector correctly)
We have switched routers recently. I dont think this is the cause because ports 25 (SMTP) and 53 (DNS) are forwarded to our server.
Thanks for your help in advance.