Send-AS hybrid public folder

[Peter Wohlers]

Hi,

I have an Exchange 2013 in configured in hybrid and have public folders in hybrid mode also.

I have migrated some users to O365, now they cannot use send-as on mail enabled on-prem PF.

Is there way to solve this? They had this before migration and it was working.

/Peter

[#2 · Accepted solution]

Cross-premises Send As/Send on behalf of permissions are NOT supported.

[#3]

If this is not supported, I have successfully found a workaround that makes Send on Behalf work anyway, so I'd be happy to share how to achieve this in a Hybrid scenario.

If a user needs to send on Behalf of a Public Folder, which resides in on-premises Exchange in the current Hybrid configuration, the following steps are necessary:

1. Ensure that the user has the permissions assigned in the On-Premises EAC:
   Public Folders > *Your PF* > Edit > Delivery Options (Send As or Send on Behalf)
2. In ADUC, find the Active Directory object corresponding to the Public Folder. It would have the same name as the public folder.
3. Open Properties > Security and Add..., pick the user and Allow Send as permissions on the PF object, then save.
4. Connect to Office365 through the Exchange Online PowerShell Module and execute the following command:
   Set-MailPublicFolder "PrimarySMTPofyourPublicFolder" -GrantSendOnBehalfTo "UserUPN"
   
5. The user with their Office 365 mailbox will now be able to Send on Behalf of the Public folder
   
   

So far, I only needed to set up Send on Behalf and not Send As permissions, but I'd expect the implementation to be nearly identical apart from the PowerShell command.

I believe the cmdlet for Send As would be:
Add-RecipientPermission -Identity <publicFolder> -Trustee <UserUPN> -AccessRights SendAs