exchange 2010

We have serious problem with mails . Users are sending mails, but they just disappear. They are not even leaving trace in "sent"-items. Mostly sales people are reporting that customers are not receiving mails they have sent.
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

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.

FOXActive Directory/Exchange EngineerCommented:
Have you checked your message ques on the server?
I would confirm the queues as FoxLuv noted above but i would also test the send/receive options from within Outlook Web access, this will help you isolate the issues from either the client or server side. If all emails are flowing via the webapp without issue then you know this is a client side issue, look at the outlook profiles.  Do you have any Smarthosts where you can track or Log the flow of the messages outside of the exchange?

Are all users local to the network or are they sending from remote locations?
Do the emails pass thought and firewall device with email management software included that maybe stripping the traffic/messages?
Are these single emails and/or mail merges

I would start a series of tests emails, include the following addresses:

and see if you can isolate the issue, if they deliver internal but not external that will give you a starting location for the troubleshooting. If they do not arrive at either address complete the above test via the webmail and confirm.

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
pramod1Author Commented:
I saw the incident today there are no messages in queue, BTW how long messages are there in queue viewer

and these mailboxes are in o365
Messages only sit in the Queue until they are sent, so from the time the server receives them until it manages to pass them onto the destination. You normally see large queues when users are sending mail merges and/or if the server its self has issue resolving domain names and/or forwarding to a designated smart host.
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
Email Servers

From novice to tech pro — start learning today.