How do I upper case an email address?

Question

I expect this should be a pretty easy question. It is in two parts:

1. Are email addresses case sensitive? (i.e. is [email protected] different from [email protected]?)
2. If so, what is the correct locale to use for capitalising an email address? (i.e. capitalising the email [email protected] would be different in the US and Turkish locales)

Answer 1

Judging from the specs the first part can be case sensitive, but normally it's not.
Since it's all ASCII you should be safe using a "naive" uppercase function.

Check out the RFC spec part of the wikipedia article on E-mail adresses

If you're in for some heavier reading RFC5322 and RFC5321 should be useful too.