Couldn't find a forum section dedicated to email issues so thought I'd just post this here:

I have users sending from an Exchange 2003 domain smithandhall.com.au to GMail and Hotmail accounts that are now suddenly not going through. Messages do not show up in GMail or Hotmail inboxes, trash or junk mail folders. No delivery failure messages are being returned to the senders either. I suspect the domain may have been blocked by GMail and/or Hotmail but am unsure how to verify this. The reason for my suspicion is that they send out mass emails of up to 20,000 (not just to GMail and Hotmail accounts) every so often that are legitimate messages however I believe this may be reason for GMail to flag this domain as a spam distributer. Is there a way to check this and/or request it's unblocking? I have run several SMTP tests via telnet that do go through and do not indicate any problems however no messages from Outlook 2007 or Web Access are being received by GMail.

Appreciate any help with this issue.

Possibly no reverse DNS lookup

Thanks Chris. Have got a PTR record added to the domain however still no go is there anyway you know of to verify that it is being blocked by GMail/Hotmail?

Cheers.

The PTR records need time to propagate fully before writing it off (96 hours (four days) max).

check the RBL lists for your IP/hostname
http://mob.net/~ted/tools/rbl.php3
http://www.mxtoolbox.com/SuperTool.aspx

Have you found what the issue is?

We are having exactly the same problem.
Not blacklisted (I checked as per above)...

Thank you!

Gabe.

I work with a major web Hosting company and we see the big e-mail sites like Gmail, Yahoo, Hotmail,etc... Just toss out e-mails that seem to be "forwarded" to them.

There seems to be no errors and no explanations---and of course, Nearly impossible to get tech help from these big-boys.