How to Validate Email Addresses with Perl

Is it valid, and will it work? If you collect or use email addresses anywhere in your Perl scripts and programs, you possibly collect many addresses that do not work. One may lack a letter in the domain name, another may have a disallowed character.

Whatever the reasons for its invalidity, you do want to catch the broken address — to prompt the user to re-enter maybe, or to avoid sending an email that's sure to go nowhere.

In Perl, you can concoct a complicated regular expression, of course; or you turn to a handy module that already has one built in and can check domain names, too.

To check email addresses for the well-formedness and validity in a Perl script or program:

• Build email validation into the HTML code if you have users type email addresses into a web form.
• Use Email::Valid->address('') from the Email::Valid CPAN Perl module; see below for details, installation and examples.

Assuming $email_address holds the address to be checked, you can check its validity using:

#!/usr/bin/perl

use Email::Valid

$email_address = 'me@@example.com';

if (Email::Valid->address($email_address)) {

 # The email address is valid

} else {

 # The email address is not valid

}

You can also have Email::Valid check for valid top-level domains (making sure ".com", ".net", ".cn" or another valid domain name is at the email address's very end). Make sure the Net::Domain::TLD module is installed.

#!/usr/bin/perl

use Email::Valid

$email_address = 'me@@example.com';

if (Email::Valid->address(-address => $email_address,

 -tldcheck => 1)) {

 # The email address is valid

} else {

 # The email address is not valid

}

To equip your Perl installation with the Email::Valid module for validating email address correctness:

• Open a command prompt.
  • Under Mac and Linux, open the Terminal application, for example.
• Type

  sudo perl -MCPAN -e 'install Email::Valid'

  (Mac and Linux) or

  perl -MCPAN -e 'install Email::Valid'

  .
• Press Enter.
  • Enter the super user password and press Enter if prompted.
  • Asked Would you like me to configure as much as possible automatically?, choose "yes" unless you know
  • Asked Is it OK to try to connect to the Internet?, enter "yes" as well.