The problem:
A public folder in Office 365 Hosted Exchange will be assigned a @onmicrosoft.com address by default. And there is of cource no way of changing this to your primary domain.
Solution:
Conncect to the Windows Azure Active Directory Module for Windows PowerShell using the following commands.
Create a placeholder for your credentials:
$LiveCred = Get-Credential
Popup box will ask for your Office 365 Global Administrator credentials.
Create a placeholder for your Powershell Session towards Exchange Online.
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://ps.outlook.com/powershell/ -Credential $LiveCred -Authentication Basic -AllowRedirection
Import your Powershell Session to connect to Exchange Online.
Import-PSSession $Session
Run this command to allow all scripts:
set-executionpolicy unrestricted
Then run the following command to disable the Policy for assigning email Adresses in public folders.
Set-MailPublicFolder -Identity “\” -EmailAddressPolicyEnabled $False
Now, in your Office 365 tennant web admin go to Exchange – Public Folders – Highlight the public folder (email enabled) – Click the pencil (edit) – Click on Email Address – highlight the address you want to use as default – Click pencil – Check the default email address checkbox.
Save, close and test.
