How to change public folder default reply address in Office 365 (Couldn’t update the primary SMTP address)

By default a public folders’ email address in Office 365 gets the onmicrosoft.com address as the reply address. It would be nicer to have the company’s default email address as reply address.

To adjust the PrimarySMTPAddress, run the Set-MailPublicFolder cmdlet with the PrmarySMTPAddress parameter

Set-MailPublicFolder -Identity mypf@itexperience.net -PrimarySmtpAddress mypf@itexperience.net

In my case however, I encountered this error:

WARNING: Couldn’t update the primary SMTP address because this mailbox is configured to use an email address policy. To disable the email address policy for this mailbox, run the command with the EmailAddressPolicyEnabled parameter set to $false.

I firstly had to disable the EmailAddressPolicy. To do so, run

Set-MailPublicFolder -Identity mypf@itexperience.net -EmailAddressPolicyEnabled $False

After this, I could change the SMTP address:

Set-MailPublicFolder -Identity mypf@itexperience.net -PrimarySmtpAddress mypf@itexperience.net

You can also change the default SMTP address of a public folder using the Exchange Online GUI:

But note that the checkbox “Make this the reply address” is only available after you have set the EmailAddressPolicyEnabled to $false. For more information about the Set-MailpublicFolder can be found here