PHP Form Only Submitting Emails From Gmail and No Other Addresses - php

Question

I have an html from. When the user submits the form, I'm sending an email to the given email address using php. Emails to gmail accounts go through perfectly fine. However, mails to providers like yahoo, aol etc does not go through.There is no filter mechanism in my code to filter out email addresses. Some mails to yahoo mail addresses goes through rarely. But aol doesn't go at all. What is the issue here?
My html code:
<section class="contact-container">
<div class="container mtb">
<div class="row">
<div class="col-md-8 wow fadeInLeft">
<h4>Get in touch</h4>
<hr>
<p>Leave a comment, review, or general musings.
</p><br/>
<form method="post" id="captcha_form" name=
"captcha_form" action="mailform.php"><fieldset><ol>
</li><li><label class="solo" for="email">Email address:</label>
<span class="required">(required)</span><input type="text" class="solo
input" name="email" id="email" value="" />
</li><li><label class="solo" for="name">Name:</label><input type=
"text" class="solo input" name="name" id="name" value="" />
</li><li><label class="solo" for="subject">Subject:</label>
<span class="required">(required)</span> <input type="text" class=
"solo input" name="subject" id="subject" />
</li><li><label class="solo" for="message">Message:</label>
<span class="required">(required)</span>
<div class="solo input"><textarea class="solo input" name="message" id=
"message" ></textarea><br />
<p><input name="submit" id="submit" type="submit" value="Send" style=
"float: right;" /></p></div>
</li></ol>
</fieldset></form> <br /> <br />
</div>
And here is snippets of mailform.php:
<?php
$dontsendemail = 0;
$possiblespam = FALSE;
$strlenmessage = "";
$email = $_REQUEST['email'];
$message = $_REQUEST['message'];
$subject = $_REQUEST['subject'];
$emailaddress = "email#gmail.com";
/ Check human test input box
if(isset($_REQUEST["htest"]) && $_REQUEST["htest"] != "") die
("Possible spam detected. Please hit your browser back button
and check your entries.");
// Check email address function
function checkemail($field) {
// checks proper syntax
if( !preg_match( "/^([a-zA-Z0-9])+([a-zA-Z0-9._-])*#([a-zA-Z0-9_-])+
([a-zA-Z0- 9._-]+)+$/", $field))
{
die("Improper email address detected. Please hit your browser back
button and enter a proper email address.");
return 1;
}
}
// Spamcheck function
function spamcheck($field) {
if(preg_match("/to:/i",$field) || preg_match("/cc:/i",$field)
|| preg_match("/\r/i",$field) || preg_match("/i\n/i",$field)
|| preg_match("/%0A/i",$field)){
$possiblespam = TRUE;
}else $possiblespam = FALSE;
if ($possiblespam) {
die("Possible spam attempt detected. If this is not the case, please
editthe content of the contact form and try again.");
return 1;
}
}
if ($dontsendemail == 0) {
$message="";
$message.="Name: ".$name."\r\n";
$message.="Mailing Address: \r\nLine 1: ".$addressline1."\r\nLine
2: ".$addressline2."\r\nCity: ".$city."\r\nState: ".$state."
\r\nZip: ".$zip."\r\n";
$message=$message."\r\nMessage:\r\n".$_REQUEST['message'];
mail($emailaddress,"$subject",$message,"From: $email" );
include "email_sent.php";
echo "Thank you, I will respond shortly.";
}

Answer 1

Don't use a regex to confirm email addresses. The real regex is like a day long. Use http://www.w3schools.com/php/filter_validate_email.asp or https://code.google.com/p/php-smtp-email-validation/ or https://github.com/appskitchen/emailverifier/blob/master/class.emailverify.php . You'll notice they are much more complicated than a basic regex. The email spec is insane: https://www.rfc-editor.org/rfc/rfc2822