[UA-discuss] Regular Expression

Tan Tanaka, Dennis dtantanaka at verisign.com
Tue Sep 12 19:09:32 UTC 2017

David, good article.

A couple of excerpts …

“Just send them an email already
No, I’m not joking. Just send your users an email. The activation email is a practice that’s been in use for years…”

“If you really, really want to make sure people are typing in an actual email address, just use the /@/ regular expression and call it done. If that makes you nervous, then check for the dot too: /.+ at .+\..+/i. Anything more is overkill.”


From: <ua-discuss-bounces at icann.org> on behalf of David Conrad <david.conrad at icann.org>
Date: Tuesday, September 12, 2017 at 2:52 PM
To: Don Hollander <don.hollander at icann.org>
Cc: "UA-discuss at icann.org" <ua-discuss at icann.org>
Subject: [EXTERNAL] Re: [UA-discuss] Regular Expression


Perhaps also pointing people at https://davidcel.is/posts/stop-validating-email-addresses-with-regex/?


On Sep 12, 2017, at 11:44 AM, Don Hollander <don.hollander at icann.org<mailto:don.hollander at icann.org>> wrote:

Please note that this is a Geeky post - so carry on if that’s not you.

Email validation is an area where many websites fall short as we found in our study on Website UA Readiness (nearing publication)

The technologies behind these websites generally use a Regular Expression as their first line of defence against rubbish data.   The issue is that most of these RegExs are overly restrictive.

As an appendix to the Website review, we looked at some of the technologies behind the websites to see if there were common denominators for good and bad experiences.

One RegEx has stood out as being simple and correct.   I’d like the UASG to consider recommending this in our documentation.   Toward that end, this thread is for discussion.


Regular expression check in Javascript. This accepts any Unicode characters, only insisting that the domain must have more than one label and the TLD is 2 characters or longer.

Your thoughts?

Don Hollander
Universal Acceptance Steering Group
Skype: don_hollander

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mm.icann.org/pipermail/ua-discuss/attachments/20170912/5f0ce28b/attachment.html>

More information about the UA-discuss mailing list