I've frequently been troubled by users signing up with fake email addresses. I know that validating email through sending emails on validation helps, and we are doing this. However, in the instance where the email is fake, and the person requests several validation emails, this can lead to hotmail and other mail providers temporarily blocking you. I've had that happen a few times at www.it-globalized.com and other sites that I've been running.

However, I did some research and came up with an approach which works very well for sign-ups. It took a while to nut out the technical side of things, but in the end it worked.

I've also made the solution into DLLs so others who face a similar issue can use this approach as well, and made a little demo of it on this page: http://www.it-globalized.com/email_validate.aspx

Anyway I thought this might be relevant for discussion in the Email Forum. Have any others had other similar issues with email or hotmail? What have your approach been to resolving those issues? And not the least, have those approaches bee successful?

Just wanted to mention that as we have recovered the cost of developing the ITG Email Validator, we have reduced the price to USD 0.99.

Any further profits will be used to develop other useful tools and resources for developers.

Seems to be a problem with your DNS servers. The validator was not able to retrieve my MX records:

We don't have DNS servers, so it can't be a problem with that ... It is a challenge with the query we send to your DNS server, from which your DNS returns "" as the MX record for this domain.

What is the "code" bit you have attached to this post? Is that the details contained in the MX record?

This has happened on two occasions previously as well, so I will investigate the matter further given that it does seem like you do have a valid MX record. I've got an idea of what we can do. There may be some additions we can make the the query to do an additional query if the initial result is blank. Will post another post when I have investigated the matter further.

Hi Nathan

I have made updates to the validation to cover the scenario which occurred to your email address. Can you give it a go again?

dig is a DNS lookup tool.

What that code does is query the DNS server for the MX record for my domain. My DNS server was resolving the record correctly at the time, and I would hope so because each of HostMySite's name servers are load balanced between multiple servers.

Running the test now, I don't have the same problem.

I'm actually interested in this software because I was working with something similar using PHP. I designed a SMTP test tool that uses sockets to connect to the recipients mail server, and send an email, I was going to expand this to validate user's emails when registering for my site, however I think an email validation link serves this purpose equally well if not better (I have yet to implement this).

Your software is very interesting, and highly useful, but coming from a Linux Background, I can't integrate it. I code in Ruby, and it is unlikely that your team will find a significant market there, but I would really appreciate it if you could port it to PHP.

Hi nathacof

Yep, this is a similar thing, it is in essence a SMTP test tool that uses sockets to verify the address in several steps.

I think both are quite good. The email validation with a code is definitely good, and we use this too, but I find that having these checks enable us to get less erroneous email in the sign-ups up front in the system to start with - i.e. less bounced emails to bad addresses.

I've put in a little readme on how we did implement the DLLs on IT-Globalized.com. I'll probably also add the regex we used for the email to this readme file.

http://www.it-globalized.com/images/emailvalidator/readme.txt

comprug

Given that this is implemented as two DLLs, you could probably use this in a PHP site as well as long as you've got .net framework on the server that is. Not completely sure, but if you would like to give it a go, I can send you some demo DLLs. Maybe check the readme file for how I call the DLLs in VB.net...

I might do some further investigation into the possibilities of that as well.

If anyone needs to know how to implement this in PHP on Linux send me a PM and I can give you some pointers.