421 4.4.2 connection dropped issue with exchange 2007
Posted on 2011-10-11
I seem to be having some bother with an exchange 2007 server - some mails seem to get queued with the error:
421 4.4.2 connection dropped.
There is a valid PTR record set up (I have confrimed this) and there doesn't appear to be anything unual going on with the exchange set up.
The domain has 4 mx records set up to direct to googles postini service and this shouldn't effect anything - this is also for incoming only. There is no other software on the server that direct relates to exchange (ie. norton etc.).
Most mails seem to send fine and a few that are queued are eventually delivered. There are a couple of domains though that they cannot send mail to at all, Delay notification and the NDR - 421 4.4.2.
When I try to telnet a mail to one of the domains it goes through fine, one of the others reports error 451 mail server temporary failed.
Any ideas what is up?