# Documented Email Regex Validation

**URL:** <https://forum.kirupa.com/t/documented-email-regex-validation/195174>\
**Category:** open source\
**Created:** [July 29, 2006, 7:12am UTC](https://forum.kirupa.com/t/documented-email-regex-validation/195174 "2006-07-29T07:12:05Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Jeff\_Wheeler](https://avatars.discourse-cdn.com/v4/letter/j/59ef9b/32.png) [@Jeff\_Wheeler](https://forum.kirupa.com/u/Jeff_Wheeler)\
**Post date:** [July 29, 2006, 7:12am UTC](https://forum.kirupa.com/t/documented-email-regex-validation/195174/1 "2006-07-29T07:12:05Z")

</div>

Alright, inspired by the other thread, I wrote a regular expression in a Python function which will return a boolean whether or not the email is valid.

I followed the rfc ([http://www.faqs.org/rfcs/rfc822.html](http://www.faqs.org/rfcs/rfc822.html)) word-for-word. It is, as far as I know, _exactly_ the same, except for support of ASCII characters 0x000-0x037 and 0x177 (those are special characters such as EOF, and backspace, which should be taken care of outside the script).

```auto
def match_email(address):
    import re
    mail_re = re.compile(r'(?#addr-spec)((?#local-part)((^|\.)((?#word)((?#quoted-string)"((?#quoted-pair)\\.|(?#qtext)[^"\\])+")|((?#atom)[^()<>@,;:\\".\[\] ]+)))+)@((?#domain)(?<=@|\.)((?#sub-domain)((?#domain-ref)((?#atom)[^()<>@,;: \\".\[\]]+))|((?#domain-literal)\[((?#dtext)[^\[\]\\]|(?#quoted-pair)\\.)+\])+)+($|\.)){2,}$')
    return mail_re.match(address) != None

# Use like this:
print match_email(r'jeff@nokrev.com')

```

Some sample **valid** email addresses (believe it or not… just look at the rfc linked above):

```auto
"@ad \f".he."s\"".llo."@"@site.c[\]]m
"\"".hey." "@domain.doma["i"]n.domain
"\""."more".hey."@ @"@doma["i"]n.co.uk!

```

And some **invalid** ones:

```auto
"@ad \f"he."s\"".llo."@"@site.c[\]m
""".hey.""@domain.doma[]n.domain
@.com

```

[whisper]Sorry for the bad samples… hehe.[/whisper]