Hi,
Bit of history first. We have recently installed an Exchange 2K3 server (on an 2K3 DC). Previously we had our mail hosted by an ISP and connected via pop3.
Now via our new Exchange server we are unable to send email to one particular domain. Each time we get the bounce :-
"Your message did not reach some or all of the intended recipients.
Subject: test
Sent: 18/10/2004 14:35
The following recipient(s) could not be reached:
info@thierdomain.com on 18/10/2004 14:35
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<mailserverhostname.ourdomain.co.uk #5.5.0 smtp;550-Verification failed for <Administrator@ourdomain.co.uk>>"
Now then, firstly, the recipients mail server is hosted by the same ISP who used to host ours.
As we still have our pop3 mailboxes open with the ISP, we have successfully tested our ability to send to thier mail server via this route. Its only when sending via our exchange server that we get the fail.
Our external DNS as well as thier external DNS is also all hosted by the same ISP. Therefore weve been in contact with the ISP and they checked the relevant records, and that rDNS is enabled correctly etc etc etc. and they are pointing the finger at our mailserver being the problem, since if we send via our old pop3 account hosted by the isp, we dont get bounced.
Has anyone ANY ideas, no matter what I find on the web it all points to external DNS problems, but the ISP is claiming it must be our end at fault - should I believe them?
Many thanks
Bit of history first. We have recently installed an Exchange 2K3 server (on an 2K3 DC). Previously we had our mail hosted by an ISP and connected via pop3.
Now via our new Exchange server we are unable to send email to one particular domain. Each time we get the bounce :-
"Your message did not reach some or all of the intended recipients.
Subject: test
Sent: 18/10/2004 14:35
The following recipient(s) could not be reached:
info@thierdomain.com on 18/10/2004 14:35
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<mailserverhostname.ourdomain.co.uk #5.5.0 smtp;550-Verification failed for <Administrator@ourdomain.co.uk>>"
Now then, firstly, the recipients mail server is hosted by the same ISP who used to host ours.
As we still have our pop3 mailboxes open with the ISP, we have successfully tested our ability to send to thier mail server via this route. Its only when sending via our exchange server that we get the fail.
Our external DNS as well as thier external DNS is also all hosted by the same ISP. Therefore weve been in contact with the ISP and they checked the relevant records, and that rDNS is enabled correctly etc etc etc. and they are pointing the finger at our mailserver being the problem, since if we send via our old pop3 account hosted by the isp, we dont get bounced.
Has anyone ANY ideas, no matter what I find on the web it all points to external DNS problems, but the ISP is claiming it must be our end at fault - should I believe them?
Many thanks
