Comments on: Check Email Address with JavaScript and Regular Expressions

By: gemp

gemp — Thu, 07 Aug 2008 14:25:02 +0000

There’s much simpler way to write the expression:
var regex = /^[a-z0-9\._-]+@([a-z0-9_-]+\.)+[a-z]{2,6}$/i;
- With the final modifier /i there’s no need to indicate the upper case range.
- I don’t know of any TLD with numbers in it.
On a side note, I do allow TLD with up to 6 chars; new ones arrive regularly and you never know (well, somme future ones may even have numbers in it, I know).

By: Android

Android — Thu, 24 Jul 2008 10:32:50 +0000

Perfect, just what I needed!

By: Douglas Karr

Douglas Karr — Fri, 02 Nov 2007 15:23:04 +0000

Hi Reg,

You can test out the Regex utilizing an Online Regex Tester.

Also, there’s definitely much more that can be done if you want to ensure an email address is valid in accordance with the RFC.

There are a few reasons not to allow someone to enter an invalid email address:
1. They will get annoyed at you when the email they expected doesn’t get through - regardless of whether or not it was your fault the address was entered incorrectly.
2. If com.museum was a valid domain and, let’s say, Yahoo! operated it - any email address that bounced would have a negative impact on your company’s reputation for email delivery. This could lead to all of your company’s email being blocked.
3. If your email service provider allowed you to enter bob@com.museum, you’d also pay for each email sent to that email address until they unsubscribed that address due to bounces. I would steer clear of any ESP that would allow an invalid email address like that - they’re just taking your money!

Thanks for stopping by!
Doug

By: Reg Braithwaite

Reg Braithwaite — Fri, 02 Nov 2007 03:37:41 +0000

I like the idea, but I would be hesitant to adopt this particular regular expression without description of which legal email addresses it does not accept and which illegal addresses it permits.

For an example of a regular expression that does a decent job alongside an explanation of which cases it does not cover, see this:

http://www.regular-expressions.info/email.html

My personal preference is to cover most of the simple cases and issue a warning for everything else rather than rejecting it. If Bob really want sto submit bob@com.museum rather than bob@museum.com, why not let him?

By: Chipping the web - simple, not secure -- Chip’s Quips

Chipping the web - simple, not secure -- Chip’s Quips — Thu, 01 Nov 2007 20:00:15 +0000

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