Comments on: What is a valid email address?

By: Terry

Terry — Wed, 23 Jan 2013 15:01:30 +0000

I don’t understand any of this. Please what field of engineering is this? The only reason I surfed this page is because I keep on getting error messages stating that my e-mail [email protected], which I’ve used for donkey years, is invalid. Please help me out oh great scientists.

By: Ayanda angel

Ayanda angel — Wed, 03 Oct 2012 18:01:16 +0000

Thanks to tags for helping me about my email

By: Ayanda angel

Ayanda angel — Wed, 03 Oct 2012 17:56:21 +0000

Yes it is helpful to have email e.g to apply omline,to chart via internet. So I will appreciate if you allow me to have an email

By: Michael

Michael — Tue, 02 Nov 2010 23:16:14 +0000

I’ve taken your advise. There’s now revision control and documentation/comments.

By: hm2k

hm2k — Mon, 25 Oct 2010 23:17:25 +0000

http://www.validemail.org has been updated.

@Michael Your script is poorly maintained, consider using revision control.

By: hm2k

hm2k — Thu, 07 Oct 2010 22:11:55 +0000

The date is a link to the commend…

eg: http://www.hm2k.com/posts/what-is-a-valid-email-address#comment-196432

I’ll check it out.

By: Michael

Michael — Thu, 07 Oct 2010 16:46:19 +0000

I linked to it a few comments back. I didn’t want to spam your site with a second posting.

(It also explains the development of the regular expression and provides a class to make it easy to manipulate and use).

By: hm2k

hm2k — Thu, 07 Oct 2010 16:36:57 +0000

Couldn’t you have used a pastebin or better, maintain your code in a public repository?

If you do, I’ll consider adding it into production testing.

By: Michael

Michael — Thu, 07 Oct 2010 16:30:01 +0000

/^(?!(?>(?1)\x22?\x5C?[\x00-\x7F]\x22?){255,})(?!(?>(?1)\x5C?[\x00-\x7F]){65,}(?1)@)((?>(?>(?>(?>(?>(?>\x0D\x0A)?[\x20\x09])+)?(\x28(?>(?>(?>(?>\x0D\x0A)?[\x20\x09])+)?(?>[\x01-\x08\x0B\x0C\x0E-\x1F\x21-\x27\x2A-\x5B\x5D-\x7F]|\x5C[\x00-\x7F]|(?2)))*(?>(?>(?>\x0D\x0A)?[\x20\x09])+)?\x29))+(?>(?>(?>\x0D\x0A)?[\x20\x09])+)?)|(?>(?>(?>\x0D\x0A)?[\x20\x09])+))?)(?>[\x21\x23-\x27\x2A\x2B\x2D\x2F-\x39\x3D\x3F\x5E-\x7E]+|(?>\x22(?>(?>(?>(?>\x0D\x0A)?[\x20\x09])+)?(?>[\x01-\x08\x0B\x0C\x0E-\x1F\x21\x23-\x5B\x5D-\x7F]|\x5C[\x00-\x7F]))*(?>(?>(?>\x0D\x0A)?[\x20\x09])+)?\x22))(?>(?1)\.(?1)(?>[\x21\x23-\x27\x2A\x2B\x2D\x2F-\x39\x3D\x3F\x5E-\x7E]+|(?>\x22(?>(?>(?>(?>\x0D\x0A)?[\x20\x09])+)?(?>[\x01-\x08\x0B\x0C\x0E-\x1F\x21\x23-\x5B\x5D-\x7F]|\x5C[\x00-\x7F]))*(?>(?>(?>\x0D\x0A)?[\x20\x09])+)?\x22)))*(?1)@(?>(?>(?1)\[(?:(?>IPv6:(?>(?>[a-f0-9]{1,4}(?>:[a-f0-9]{1,4}){7})|(?>(?!(?:.*[a-f0-9][:\]]){8,})(?>[a-f0-9]{1,4}(?>:[a-f0-9]{1,4}){0,6})?::(?>[a-f0-9]{1,4}(?>:[a-f0-9]{1,4}){0,6})?)))|(?>(?>IPv6:(?>(?>[a-f0-9]{1,4}(?>:[a-f0-9]{1,4}){5}:)|(?>(?!(?:.*[a-f0-9]:){6,})(?>[a-f0-9]{1,4}(?>:[a-f0-9]{1,4}){0,4})?::(?>[a-f0-9]{1,4}(?>:[a-f0-9]{1,4}){0,4}:)?)))?(?>25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])(?>\.(?>25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])){3}))\](?1))|(?>(?!.*(?1)[a-z0-9-]{64,})(?1)(?>(?>xn--)?[a-z0-9]+(?>-[a-z0-9]+)*(?1)\.(?1)){0,126}(?>xn--)?[a-z0-9]+(?>-[a-z0-9]+)*(?1)))$/isD Allows a dot-atom (full character range) local part, quoted-string local part, obsolete local part (mixture of (dot) atoms and quoted strings), domain names, internationalized labels, domain literals (IPv4 and IPv6), folding white spaces and nested comments. 1,394 characters. Very long, but much shorter than other expressions which seek to completely verify an email address (Perl's infamous example). Although, the fact that it's long is irrelevant: my intention was to simply show that it can be done. I hope this is helpful. (Note: I'm hoping HTML tags work in comments -- if not, please remove "pre" tags. Thanks).

By: hm2k

hm2k — Thu, 07 Oct 2010 15:25:42 +0000

@Dominic Sayers

1. I purposely chose to link to what I’m using, instead of websites subject to change. However I will update the copy of your script.

2. I’m aware of RFC 5322. No further updates will be added to the post itself, however I may re-address the topic in a new post at a later date.

Thanks for the feedback.

@Michael

That statement was written about the same time as RFC 5322 was published so I dare say that things have changed in that time. All that aside, you should provide evidence to support such radical statements otherwise you’re helping nobody.