Possible Duplicates:
Is there a php library for email address validation?
How to check if an email address exists without sending an email?
hi guys,
how can i validate the email address to email provider just like yahoo?
scenario:
how can i validate it to yahoo.com that the email stated above is valid?
Thanks in Advance.
---- PHP Rules ----
The only "propper" way to validate an email is to actually try to send an email to that address, but most times a regular expression will do the trick.
To complicate the issue, you might just want a simple validation like this
^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,6}$
or a somewhat more complex one like this
[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+(?:[A-Z]{2}|com|org|net|gov|mil|biz|info|mobi|name|aero|jobs|museum)\b
There is a pretty good article about email validation here
Make an SMTP connection to the server, and do a 'Sender-Verify' lookup:
telnet <Yahoo MX> 25
helo here.com
mail from: [email protected]
rcpt to: [email protected]
data
You'll either get a code to proceed with transmission, or be given an recipient invalid message.
Use this free web service through either a SOAP call, GET, or POST. All you need to do is feed it an email address and it will return a boolean value representing whether or not it's an actual, deliverable email address:
http://www.webservicex.net/ValidateEmail.asmx?op=IsValidEmail
There are many spam/trash mailers out there (www.spam.la), that allow you to receive mails to any address. Therefore I suggest not to rely on a "valid" email in the usual sense. Maybe OpenID is an option? For just checking for a "valid" format you can maybe make use of existing functionality like filter_var()/FILTER_VALIDATE_EMAIL.
The following regex matches email addresses:
^([\w-\.]+)@((\[[0–9]{1,3}\.[0–9]{1,3}\.[0–9]{1,3}\.)|(([\w-]+\.)+))
([a-zA-Z]{2,4}|[0–9]{1,3})(\]?)$
[email protected] - VALID
[email protected] - VALID
[email protected] - VALID
rashmi.pandit@gmail - INVALID
[email protected] - INVALID
If you want more complex as per RFC guidelines, you can use this one:
^((([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+(\.([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+)*)|((\x22)((((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(([\x01-\x08\x0b\x0c\x0e-\x1f\x7f]|\x21|[\x23-\x5b]|[\x5d-\x7e]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(\\([\x01-\x09\x0b\x0c\x0d-\x7f]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))))*(((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(\x22)))@((([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.)+(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.?$
You could send an email to the address and have the user verify it by clicking on a link.
Most of the above answers look at regular expression check of email address. To actually see if the email address is valid you will need to connect to the SMTP server and send it commands. All details and PHP code is available here.
Use sparingly, Yahoo servers might block you if you send a lot of requests. Also it is highly recommended to use it along with the regular expressions as described by others.