Exchange 2013 - Meeting Invite from external contact is internally processed and received hundreds of times per day for one user

One of my users gets the same invite to attend a meeting hundreds of times a day. The invite was originally sent from an external contact (outside our Exchange 2013 / AD setup) and I can see that this external contact sent the request only once. The repetition is happening within our system, and the invite generated each time is identical to the last.

Somewhere within Exchange something is not right. This replication happens regardless of whether Outlook is open, and whether there are iOS devices turned on and syncing or not.

I've some vague high concept ideas what might be happening, but if anyone could give me technical specifics to carry out in PowerShell or the EAC to try and fix this, I'd be most appreciative!

Many thanks :-)
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.

Simon Butler (Sembee)ConsultantCommented:
"...there are iOS devices turned on and syncing or not..."

That would probably be the culprit. Calendar handling on iOS with ActiveSync is very poor and shouldn't be used (ie don't do anything with the calendar on the device at all).
It has probably looped and the messages are queued.

Going to be blunt here - wipe the iOS device and remove the ActiveSync partnership. Wait for the messages to flush out completely. Then resync.

All the time the iOS device is active or configured for the mailbox I wouldn't look anywhere else for the cause.

bluemercuryAuthor Commented:
Hi Simon.

Sorry, EE didn't tell me there was a message from you!

Had already tried what you've suggested when I posted, as read a lot of people saying iOS was a royal pain on this. We left it a good few hours with no ActiveSync engaged (account deleted) and the single iOS device the user has turned off. Still the repeated meeting invite messages came in.

Would you suggest we try it for a whole 24 hours, to see if it stops? Otherwise, I was going to delete and recreate the user mailbox (backup, PST export first).

Incidentally, the troubles began after a Veeam backup crashed out a load of our VMs. This does make we wonder if it is little to do with ActiveSync and more to do with some internal issue on Exchange.

Many thanks,

bluemercuryAuthor Commented:
Quick bit of follow up:

We removed all instances of the user's ActiveSync for a whole week. Problem still happened. I have indentified that it is probably something wrong in the Outlook 2010 client or the Outlook profile. The user went away on holiday for 5 days, only using ActiveSync on their iOS device (having reinstated). No problems at all. Having got back, the invitations started again as soon as they fired up the Outlook client. They have two instances of Outlook - one on their workstation, one on their laptop, so I'm investigating whether it is either or both and trying to fix this now.

Thanks for your efforts in trying to help - from all I read iOS was looking the likely culprit, but in this case seems to have been the device not causing trouble!


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
bluemercuryAuthor Commented:
Worked out on my own accord that the problem is with the Outlook client....
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

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.