Exchange 2016 removing apostrophes from addresses

New Contributor

We have two Exchange 2016 servers in a DAG with CU19. We haven't performed any patches for a couple months now.


All of our addresses that contain apostrophes are being truncated for no obvious reason. The apostrophes are just removed and started occurring last week.  Active Directory still contains them in the username and last name, so we have no idea how this could happen.


The Default Policy is applied to the organization with First Initial, Last Name...


Email Address Format



Address 2:



The last name fields requiring apostrophes are still present, as stated.


Any thoughts?

2 Replies

And here's another odd thing.  End users, when trying to email these missing apostrophe accounts, are getting an error...


"We won't be able to deliver this message to "John Smith", because the email address is no longer valid."


Interestingly, the message still delivers despite the warning.  Clearing the Outlook cache doesn't matter either.