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

The short answer is that there are 2 answers. There is one standard for what you should do. ie behaviour that is wise and will keep you out of trouble. There is another (much broader) standard for the behaviour you should accept without making trouble. This duality works for sending and accepting email but has broad application in life.

For a good guide to the addresses you create; see: http://www.remote.org/jochen/mail/info/chars.html

To filter valid emails, just pass on anything comprehensible enough to see a next step. Or start reading a bunch of RFCs, caution, here be dragons.