email validator does not accept single letter subdomains

[volsung@…]

The validator for an EmailField does not accept email addresses which contain a single letter subdomain. For example: iamnotauser@… is rejected.

I would suggest a patch, but I think I would need to be a cyborg to understand the regular expression in django/core/validators.py:

email_re = re.compile(r'^((([\t\x20]*[!#-\'\*\+\-/-9=\?A-Z\^-~]+[\t\x20]*|"[\x01
-\x09\x0B\x0C\x0E-\x21\x23-\x5B\x5D-\x7F]*")+)?[\t\x20]*<([\t\x20]*[!#-\'\*\+\-/
-9=\?A-Z\^-~]+(\.[!#-\'\*\+\-/-9=\?A-Z\^-~]+)*|"[\x01-\x09\x0B\x0C\x0E-\x21\x23-
\x5B\x5D-\x7F]*")@(([a-zA-Z0-9][-a-zA-Z0-9]*[a-zA-Z0-9]\.)+[a-zA-Z]{2,}|\[(([0-9
]?[0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\.){3}([0-9]?[0-9]|1[0-9][0-9]|2[0-4][0-
9]|25[0-5])\])>[\t\x20]*|([\t\x20]*[!#-\'\*\+\-/-9=\?A-Z\^-~]+(\.[!#-\'\*\+\-/-9
=\?A-Z\^-~]+)*|"[\x01-\x09\x0B\x0C\x0E-\x21\x23-\x5B\x5D-\x7F]*")@(([a-zA-Z0-9][
-a-zA-Z0-9]*[a-zA-Z0-9]\.)+[a-zA-Z]{2,}|\[(([0-9]?[0-9]|1[0-9][0-9]|2[0-4][0-9]|
25[0-5])\.){3}([0-9]?[0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])\]))$')

[volsung@…]

The RFC822-compliant regex posted in ticket #1288 fixes this problem.

[Adrian Holovaty]

(In [2367]) Fixed #1275 and #1288 -- Change e-mail address validator regular expression to be faster, simpler and accept subdomains