$a = ‘From: senders_email_address@yourdomain.com‘ . “\r\n”; // Sender’s Email Address

$b = ‘Return-Path: senders_name /n’; // Indicates Return-path

$c = ‘Reply-To: senders_name /n’; // Reply-to Address

$d = ‘X-Mailer: PHP/’ . phpversion(); // For X-Mailer

$e = ‘”Content-type: text/plain; charset=iso-8859-1″‘; // Set Content Type For Text Email

$result = $a.$b.$c.$d.$e;

Put this inside the “public function CreateHeader()” in your class.phpmailer.php

“Why we can send email to Gmail or to any other free email provider, but why in Yahoo sometimes can’t?”
“Why sometimes our email to Yahoo is delayed?”
“Why sometimes our email to Yahoo goes to Bulk/Spam folder?”

For many years, Yahoo didn’t come up any information about this problem?
This is possibly for some reasons:
1. Yahoo email is FREE, don’t expect too much. If you need more, get thier Yahoo business email
2. Yahoo priorities thier member internal emails rather than email comes from outside.
– Yahoo promote thier own service, if you want to solve this problem, get a Yahoo account and use it to send email to other Yahoo member.
3. Don’t send email more than 20 emails to to any Yahoo member per hour/day or else Yahoo will tag your IP/domain as bulk sender.
-When your IP/Domain is tagged, all emails from you will goes Bulk/Spam Folder.
3. Yahoo don’t provide technical support to any of thier free service. There is no other way to contact them.

Hope this few info can help.