We have problem on Outlook 2013 with Exchange 2010. We have diffrent shared mailboxes, that other members of the team can see the inbox and send a mail with that mailbox e-mail adress. I use here as example: Display name XXX, E-Mail Adress: xxx@tld.com
To handle the send persmissions, we have an AD group. All users in this group have the permission at the exchange server, to send mails with the mailbox XXX. The feature "Send on behalf" we don't use in in this constellation.
Since around four months, we have sometimes an issue when sending mails as XXX. When we send a mail with the mailbox XXX, it can happen that we get a mail from the exchange server saying, we don't have the permission to send a message in behalf of this user. If i check the sent mail, the sender is "XXX on behalf of XXX (xxx@tld.com)". If i send the mail again with the same settings, then it's delivered sucessfully. But it can also happen, that we still get the above error, when we send the mail again.
Anybody have an idea, why Outlook is sending the mail sometimes on behalf of, what it shouldn't, but most times it sends the mail correct?
The only solution i found until now, is to delete the "from" cache and also the rest of outlook cache. But this doesn't help. The strange thing is, this happens since around four months, before we never had this issue.
Kind regards
