Regular expression form email validation not working

Question

1.00/5 (1 vote)

See more:

Trying to validate EmailID with RE. It validates emailID only except domain name added after "dot".

i.e. if I put emailID info@abc.2323, this still works, even though I have entered wrong/invalid domain.

How can I validate email id against valid domains exist.

Thanks in advance...

Posted 12-Aug-15 21:50pm

sam7one

Updated 12-Sep-22 17:48pm

Add a Solution

5 solutions

Solution 1

You could ping the domain to see if it exists, but it is possible to have an email address with a domain that is not publicly visible.

The best way is to let the user add anything they like but send an authentication email to the account to confirm it.

This will only work if the email is there own.

You could also flag bad email addresses after you have received a address-not-found response.

To be sure, there is no 100% silver bullet. The best method depends on your specific needs

Posted 12-Aug-15 22:04pm

Andy Lanng

Comments

Sergey Alexandrovich Kryukov 13-Aug-15 4:12am

Makes sense, 5ed.
See also Solution 2.
—SA

Solution 2

In addition to Solution 1: see also https://en.wikipedia.org/wiki/Email_tracking[^].

The bottom line is: this all works only for mail agents which voluntarily agree to support one or another way of tracking. So, in practice, you can do it only withing your organization or perhaps with some of your business partners, based on mutual agreements. Typically, no method are really supported, because it would increase the level of spamming.

—SA

Posted 12-Aug-15 22:12pm

Sergey Alexandrovich Kryukov

Solution 4

C#

var re = /^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i;

Posted 12-Aug-15 23:43pm

PrTk Gupta712

Solution 5

Thanks for help from all guys...
Overall conclusion shared of not validating domain name seems to be correct.
Will share this aspect with user and see if we can skip this part. Else will ask user to provide list of domains to be allowed and validate them...

Posted 13-Aug-15 0:18am

sam7one

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

F-ES Sitecore · Accepted Answer · 2015-08-12T22:21:00

You can only validate the text is of the something something@something.something, you can't verify if the email itself is valid or the domains are valid. You're better off not doing any validation on the email at all, you'll only end up rejecting addresses that are genuine because they don't match your regex. The only way to verify the address is valid is to send it an email with a validation link the user needs to click on to say the address is real.