Hello everybody!
We have encountered an issue which seems a complete mystery to us all...
In the company we work for they use Exchange Server 2010. When configuring a shared mailbox on some Outlook clients and sending emails, Outlook sends several "copies" of the same message to its recipients.
First of all they get stuck in the outbox, but sent anyway. Just one mail is saved in the "Sent items" folder.
After tracing an example, we noticed that the messageID is different for each copy, and the Exchange server that transfers them is also different.
This happens JUST for internal addresses, when sending a message to another domaine everything is correct.
It does NOT occurre all the time nor for all users of that account; sometimes it would, sometimes not. Although there are some for whom it never happens.
People who encounter this problem are in a different geographical area than those who don't.
These people do have also other accounts for which it works correctly.
First we thought of a network problem; but when sending directly from OWA everything is correct too.
Parametres are OK, no rules are established, Office re-install has not resolved the problem either.
The most confusing is the fact that it seems to be geographically bound anyway as we are not able to reproduce the issue on our own workstations.
Thank you very much in advance for any idea you could give us.