Quotation Marks in Email Name

We have a user who is getting their emails rejected by Postie as an unknown user. I’ve checked and the correct email address is in the users account in WordPress.

The user has quotation marks in his name on the email (i.e. Joe “Nickname” Lastname <[email protected]>). I’m guessing this is the cause, but was wanted to check before I tell the guy he needs to change his email name.

Thank you!