I am an exchange administrator for a company, and I am looking for a little help on troubleshooting delayed and failed emails from Hotmail or MSN accounts to our company domain. I have no reports of other domains having issues delivering to our domain.

 Here is a little about our setup. We are in a mixed Exchange Environment at this time. I am in the process of migrating from Exchange 2007 to Exchange 2010. We use Symantec Messaging Gateway as our edge server.

Here is what I have gathered to this point. About 90% of the emails from MSN or Hotmail are Delayed anywhere from an hour to 24 hours. We do have some that are delivered without being delayed, but seems to be random. I used MXToolbox to analyze the Message Header from an email that was delayed, and I can see that the delay is between our Symantec Gateway and Hotmail's server. I also have looked at the delayed bounce back message and it had an error code of 4.4.7. Which means that it timed out when trying to send to our mail server.

I have opened a case, but I don't seem to be getting anywhere with the tech assigned to my case. I am a little frustrated that I can't get him to escalate my issue, and get someone in the same time zone to speak with. I am tired of the one message a day because of the time difference. Any Help would be greatly appreciated.