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

Check for @ and . and then send an email for them to verify.

I still can't use my .name email address on 20% of the sites on the internet because someone screwed up their email validation, or because it predates the new addresses being valid.