I have a problem where emails from some of our clients do not arrive in any of our inboxes.The client doesn't receive a delivery failureI can't find anything in the logThe problem is only with some of our clients, but emails from that client will not arrive in the mailbox of anyone on our domain.Could Exchange be filtering them for some reason at our end? if so I don't know why or where the emails may be going.(You've probably guessed I'm a relative newb to configuring exchange)Any assistance would be appreciated.Thanks

Hi, You need to enable SMTP logging on the smtp virtuel server - from this log you can tell if the missing mails gets to your server at all. Do you have any antivirus/antispam software installed that could block messages from some domains? The problem could of course also be at the other end. Leif

I have SMTP Logging enabled but cant find any sign of the communication in there?The Antivirus have not domain blocking enabled I have noticed that the X400 service wasn't switch on so I have enabled this - could this have been preventing domains with x400 systems from connecting properly?

Hi, If you can find any sign of communications with the external companies - the problem is most likely at their end. You are communicating with these companies over SMTP right - X400 is not very commonly used between companies these days. Leif

Ok - Found the problem.We have just had an new website put up on a different web server and when changing the IP for the 'www' and the '@' addresses, some numpty at our hosting company deleted the MX records!I only tracked it down to this as the issue had spread to nearly all of our clients by this morning - I guess I'll just have to wait a few days for the MX to fully repopulate again