Inbox email address with TLD greater than 4 characters

The validation check for email addresses will not validate an email address that has a TLD larger than 4 characters.

There are TLD's like .foundation and .healthcare that are greater than 4 characters now.

It is a minor issue now but will become a larger problem in the future as more TLD's are created and used.

Effects: "Email address of the server", "Inbox email address", and "Email address" under User Preferences.