Are email addresses allowed to contain non-alphanumeric characters?
I'm building a website using Django. The website could have a significant number of users from non-English speaking countries.
I just want to know if there are any technical restrictions on what types of characters an email address could contain.
Are email addresses only allowed to contain English letters, numbers, _, @ and .?
Are they allowed to contain non-English alphabets like é or ü?
Are they allowed to contain Chinese or Japanese or other Unicode characters?
Answer
Email address consists of two parts local before @ and domain that goes after.
Rules to these parts are different:
For local part you can use ASCII:
- Latin letters A - Z a - z
- digits 0 - 9
- special characters !#$%&'*+-/=?^_`{|}~
- dot ., that it is not first or last, and not in sequence
- space and "(),:;<>@[] characters are allowed with restrictions (they are only allowed inside a quoted string, a backslash or double-quote must be preceded by a backslash)
- Plus since 2012 you can use international characters above
U+007F, encoded as UTF-8.
Domain part is more restricted:
- Latin letters A - Z a - z
- digits 0 - 9
- hyphen -, that is not first or last, multiple hyphens in sequence are allowed.
^(([^<>()\[\]\.,;:\s@\"]+(\.[^<>()\[\]\.,;:\s@\"]+)*)|(\".+\"))@(([^<>()[\]\.,;:\s@\"]+\.)+[^<>()[\]\.,;:\s@\"]{2,})
Hope this saves you some time.