Hi Kilo77,
We are about to migrate our 2500 staff and 300 shared mailboxes from on-prem Exchange to O365 and I have the same concerns as you regarding the pitfalls of automapping - as cool / handy a feature as it seems.
We have only ever controlled shared mailbox access via security group. In other words:
- Create the shared mailbox.
- Create the security group.
- Add users to security group.
- Grant security group full and send-as permissions to the shared mailbox.
Our users understand the process of adding the mailbox within Outlook and this method has worked perfectly for us for the last 10+ years.
Moving to O365 we obviously need to make sure that we have a handle on the process and would, in an ideal world like to continue with the above method.
Automapping is a cool feature and is certainly much less hassle for the end user as they don't have to manually add the mailbox but whilst some of the above issues can be mitigated with reg settings and the set-mailbox <mailbox name> -MessageCopyForSentAsEnabled $True , like you say, the From field is not automatically populated.
Anyway, I just wanted to echo your sentiments on this subject...
Edit. I just found this !! Have you seen this? I need to test this ASAP!!
Regards,
Graham