Email Max Length Validation is Incorrect

[kcjmowright]

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What is the current behavior?

The default angular validation marks an email field invalid for anything longer than 128 characters.
0123456789012345678901234567890123456789012345678901234567890123@012345678901234567890123456789012345678901234567890123456789012 is the longest “valid” email address angular validation will allow on an input type email. 64 characters before the @ symbol and 63 characters after the @ symbol for a total of 128 characters.

If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via https://plnkr.co or similar (template: http://plnkr.co/edit/tpl:yBpEi4).

See http://plnkr.co/edit/Lb4vJq?p=preview

What is the expected behavior?

RFC 3696 specifies a maximum of 320 characters (octets) including separators. RFC 3696 is supplanted by RFC 5321 which specifies 64 characters (octets) before the @ symbol or 255 characters after the @ symbol up to 256 characters total including separators ( See https://tools.ietf.org/html/rfc5321#section-4.5.3 ).

What is the motivation / use case for changing the behavior?

The motivation for this behavior is to be able to support, at a minimum, a RFC 5321 compliant e-mail address.

Which versions of Angular, and which browser / OS are affected by this issue? Did this work in previous versions of Angular? Please also test with the latest stable and snapshot (https://code.angularjs.org/snapshot/) versions.

Angular 1.5.10 and the latest snapshot are affected by this issue.

It looks like the behavior changed starting with angular 1.5.7. Prior versions supported longer email addresses.

Other information (e.g. stacktraces, related issues, suggestions how to fix)

[gkalpak]

You can have a valid e-mail that is longer than 128 chars:

<---------------------------------------------------------------------------------------------------------------------------- 254 --------------------------------------------------------------------------------------------------------------------------->
<----------------------------- 64 -----------------------------> <----------------------------- 63 ----------------------------> <----------------------------- 63 ----------------------------> <---------------------------- 61 --------------------------->
0123456789012345678901234567890123456789012345678901234567890123@012345678901234567890123456789012345678901234567890123456789012.012345678901234567890123456789012345678901234567890123456789012.0123456789012345678901234567890123456789012345678901234567890

The reason your address shows up as invalid is that in addition to the limitation in RFC 5321, there is an extra limitation wrt domain name "labels" (the parts of a domain name between the .) coming from RFC 1035 (which is mentioned by RFC 5321).

The current EMAIL_REGEX implementation (which among other things imposes the length limits) is a result of f3f5cf7 (and the corresponding PR: #14719). There is plenty of discussion there about the reasoning of the changes as well as pointers to resources.

I am aware that the current REGEX may not be the ultimate email validation regex, but then again there is no such thing either 😃
We have tried to keep it reasonably close to the RFC and I am happy with what we have. Keep in mind that it is just a (hopefully sane) default validation and users are free to overwrite it, according to their needs.

I am going to close this issue, since everything seems to work as expected (or at least as intended), but feel free to continue the discussion below.

[kamleshwebtech]

How to validate an email address which character size is 320 (64 characters before '@', one character of '@' and 255 characters for domain name)? Kindly share your suggestion. Thanks a lot.

[tsasioglu]

@kamleshwebtech There's some confusion around this, but an email address of 320 characters isn't valid according to the IETF. 254 is the maximum length.
https://stackoverflow.com/questions/386294/what-is-the-maximum-length-of-a-valid-email-address