What characters are allowed in an email address?

Question

I\'m not asking about full email validation.

I just want to know what are allowed characters in user-name and server parts of email address

Answer 1

You can start from wikipedia article:

• Uppercase and lowercase English letters (a-z, A-Z)
• Digits 0 to 9
• Characters ! # $ % & ' * + - / = ? ^ _ ` { | } ~
• Character . (dot, period, full stop) provided that it is not the first or last character, and provided also that it does not appear two or more times consecutively.