Validate email by MX lookup
 

This simple little hack will verify email addresses during registration and updates of profiles by doing an MX lookup against the domain to ensure somebody is accepting email for it.

It won't tell you if the actual user is valid on the domain, but it will prevent fake domains backing up in your mail spool and slowing everything down.

It requires one new error template and two simple code additions to register.php and member.php. Instructions attached.

nice man, install this asap!

Fantastic, I am soo going to install this :)

Great. :) What happens if the mail server is down though?

Most ISP's will have secondary MX and mail server. In fact, even I have a backup mail server.

If they don't have a backup, then you probably wouldn't want them registering with that unreliable address and risk clogging up your forums mail queue. :)

Ok, I was just wondering. :)
I once saw a different script that tries to connect to the server, and make sure the mailbox is really there, but then if the server was done the script will just return false.

Actually, I just realized that what I wrote was all wrong. I wasn't thinking straight.

The MX record is a DNS issue. It doesn't matter if the mail server is down. The DNS will still show that somebody should be accepting mail for it.

The only time it will fail will be if the DNS server is down or the domain doesn't have anyone accepting mail for it.

Even better. :D The other script I saw though definitely connects to the server, so this one is better.

]great hack! :) I'm tired of peeps who give they mail like i_love_vbb@coolhax0r.net or something... I'll install it! :D

Very nice!