Testing for email in a form? - php

Question

I'm working on a coming soon page. On the page I ask users to signup using their email through a form which then emails their emails to me. I'm not sure how to make sure that the data they are putting in the form are emails (to prevent spam). Any help?
Thanks.

Answer 1

Use jquery validate really easy to use http://docs.jquery.com/Plugins/Validation

Answer 2

Client side js is not enough, you should also validate with PHP's filter_var:
<?php
if(filter_var($_POST['email'], FILTER_VALIDATE_EMAIL)){
$from=$_POST['email'];
}else{
$error['email_to']='Email Invalid!';
}
?>

Answer 3

You shouldn't rely on client-side verification to keep spam and other unwanted registrations out. Although you could use jQuery validate to make the site more UI-friendly for the visitors, providing them with a neat message that the email address entered is not valid, and that they should review that field.
But a spam-bot will not care about that validation from jQuery, it will only post the fields given. That's why you need to validate the data on server-side.
There are several ways to validate email addresses with regex, but not all of them is reliable. Check out http://www.linuxjournal.com/article/9585 This article explains alot of this.

Answer 4

user following code as primary step to validate the email input
if(document.getElementById('Email').value=="")
{
document.getElementById('Email_Msg').innerHTML="Please Enter EmailId";
document.getElementById('Email').focus()
return false;
}
else
{
if(document.getElementById('Email').value.match(/^[\w\-\.\+]+\#[a-zA-Z0-9\.\-]+\.[a-zA-Z0-9]{2,4}$/))
{
document.getElementById('Email_Msg').innerHTML="";
}
else
{
document.getElementById('Email_Msg').innerHTML="Enter Valid Email-Id";
return false;
document.getElementById('Email').value="";
}
}

Answer 5

If you want to prevent spam, making sure the email field is filled in with an email field is not enough alone. Consider using a captcha like ReCaptcha

Answer 6

just have a single line validation for your email.
the code may be written like below.
<?php
if(empty($_POST['email']))
{
$error[]="Enter Email ID";
}
else
{
if(!filter_var($_POST['email'], FILTER_VALIDATE_EMAIL))
{
$error[]= "Not A Valid Email ID.";
}
}
//pass these errors to display ana error message to user.
foreach($error as $i)
{
$message = $i."<br />";
}
?>
use this code some where in your web page.
<?php
echo $message;
?>
Additionaly Use mail function and mysql database (or other if you are using) to send a mail to verify their email id. you can prevent unwanted users from registering. and also use captcha to prevent flooding to your database.
I think this helps. if any doubts reply here.

Answer 7

Create your own captcha using php gd2 library. It's easy and efficient.