How should I Go About Troubleshooting a 4.4.7 Email Delivery Error?

We have an outside client that is having trouble getting emails through to our company's domain. According to him, when he sends a message he get's the following NDR:

"Could not deliver the message in the time limit specified.  Please retry or contact your administrator.
            <DM2PR02MB365.namprd02.prod.outlook.com #4.4.7 smtp;550 4.4.7 QUEUE.Expired; message expired>"


I'm stumped as to where to even begin? Any direction would be greatly appreciated!
Scott FowlerAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

imkotteesSenior Messaging EngineerCommented:
Hi,

How are they delivering email to you? through smarthost or MX record?

If it is through smarhost then they have configured something wrongly, could DNS issue. It's good to revisit those configurations.
0
Gareth GudgerCommented:
Expired doesn't mean much. It just means Exchange finally gave up trying to resend. We need to see the error messages before the expiration. The last retry error message should tell us what is going on before it gave up.

On your side, do you see his server making a connection? If you check Message Tracking Logs or the SMTP Receive Protocol log in Exchange?

Do you have an antispam appliance or provider in play? Any reports on that?
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Scott FowlerAuthor Commented:
Thank you both for the responses!

imkottees- Unfortunately, I don't know how they're delivering emails. I've tried to get in contact with their IT department, but thus far they've been somewhat uncooperative and have been quick to assume that the issue is on our end.

Gareth- We have a Sophos antispam appliance. I checked the logs on both it and our Exchange server. As it turns out, there are some emails from the client that have gotten through in the last few weeks. Both the Sophos and Exchange box processed the emails and they did make it to the correct user's inbox. So, the problem appears to be intermittent. I see no record of any failures or rejects in our logs that are related to this clients email address.

I've done some research on my own and it does appear that the issue is likely on their end. But, as I mentioned, they won't put me in contact with their IT department, so I feel like my hands are tied. Is there anything conclusive I could look at or point to, that would tell me for certain that it is indeed on their end? Then maybe I could get a little more cooperation from them.
0
Gareth GudgerCommented:
Yep. If you have no record of it hitting your Sophos anti-spam appliance when it fails then it is not reaching your systems. Could be a DNS lookup issue on their end. Or, a problem with a smarthost if they are using one.
0
Scott FowlerAuthor Commented:
Thanks Gareth! Your suggestions pointed me in the right direction. Unfortunately, the issue turned out to be on our end. Our Cisco ASA had the "Mail Guard" security feature turned on, which was blocking incoming SSL connections. Turned the feature off and mail started flowing normally.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Exchange

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.