Zend_Mail provides several methods to set additional Mail Headers:
setReplyTo($email, $name=null): sets the Reply-To: header.setDate($date = null): sets the Date: header. This method uses current time stamp by default. Or You can pass time stamp, date string orZend_Dateinstance to this method.setMessageId($id = true): sets the Message-Id: header. This method can generate message ID automatically by default. Or You can pass your message ID string to this method. This method callcreateMessageId()internally.
Return-Path
If you set Return-Path on your mail, see Configuring sendmail transport.
Unfortunately, setReturnPath($email) method does not perform
this purpose.
Furthermore, arbitrary mail headers can be set by using the
addHeader() method. It requires two parameters containing the name
and the value of the header field. A third optional parameter determines if the header
should have only one or multiple values:
Example 582. Adding E-Mail Message Headers
<?php
$mail = new Zend_Mail();
$mail->addHeader('X-MailGenerator', 'MyCoolApplication');
$mail->addHeader('X-greetingsTo', 'Mom', true); // multiple values
$mail->addHeader('X-greetingsTo', 'Dad', true);