diff --git a/django/core/validators.py b/django/core/validators.py
index f98589578e..81bea23e36 100644
--- a/django/core/validators.py
+++ b/django/core/validators.py
@@ -23,7 +23,7 @@ ansi_datetime_re = re.compile('^%s %s$' % (_datere, _timere))
 email_re = re.compile(
     r"(^[-!#$%&'*+/=?^_`{}|~0-9A-Z]+(\.[-!#$%&'*+/=?^_`{}|~0-9A-Z]+)*"  # dot-atom
     r'|^"([\001-\010\013\014\016-\037!#-\[\]-\177]|\\[\001-011\013\014\016-\177])*"' # quoted-string
-    r')@(?:[A-Z0-9-]+\.)+[A-Z]{2,4}$', re.IGNORECASE)  # domain
+    r')@(?:[A-Z0-9-]+\.)+[A-Z]{2,6}$', re.IGNORECASE)  # domain
 integer_re = re.compile(r'^-?\d+$')
 ip4_re = re.compile(r'^(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}$')
 phone_re = re.compile(r'^[A-PR-Y0-9]{3}-[A-PR-Y0-9]{3}-[A-PR-Y0-9]{4}$', re.IGNORECASE)