We have the need for our admin assistants to be able to send email "as" a number of other users. We have a security group call "Administrative Assistants Group" to which they are all members. To add SendAs permissions to every user mailbox, we ran this command:
get-mailbox | Add-ADPermission –ExtendedRights “Send As” -user “calvaryspringfield.org\Administrative Assistants Group” | FL
Command works fine. Check the user mailboxes thru the EMC > Manage SendAs Permissions and every user shows that group having SendAs permissions. BUT, the problem is after a while, those persmissions disappear on every user mailbox. I have researched this and there are numerous reports of this occurring. One site indicated AD replication was not happening across all DCs. Checked AD Sites and found 2 decommissioned DCs still listed. Deleted those. Re-applied permissions but again they disappeared after a while. The funny thing is that this used to work and SendAs permissiones never disappeared, so maybe some correction changed the way it works. Needless to say, this can be frustrating for the admin assistancts, since they never know if it will work or not....... mostly not, because the permissions disappear shortly after being applied. Did not find a real resolution to the problem in research. Anybody got a fix for this? Exchange 2010 running on Windows 2012 Server. Please advise. Thanks.