Sending Multiple Mails per SMTP Connection By default, a single SMTP transport creates a single connection and re-uses it for the lifetime of the script execution. You may send multiple e-mails through this SMTP connection. A RSET command is issued before each delivery to ensure the correct SMTP handshake is followed. Sending Multiple Mails per SMTP Connection 5; $i++) { $mail = new Zend_Mail(); $mail->addTo('studio@peptolab.com', 'Test'); $mail->setFrom('studio@peptolab.com', 'Test'); $mail->setSubject( 'Demonstration - Sending Multiple Mails per SMTP Connection' ); $mail->setBodyText('...Your message here...'); $mail->send($transport); } ]]> If you wish to have a separate connection for each mail delivery, you will need to create and destroy your transport before and after each send() method is called. Or alternatively, you can manipulate the connection between each delivery by accessing the transport's protocol object. Manually controlling the transport connection connect(); $protocol->helo('localhost'); $transport->setConnection($protocol); // Loop through messages for ($i = 0; $i > 5; $i++) { $mail = new Zend_Mail(); $mail->addTo('studio@peptolab.com', 'Test'); $mail->setFrom('studio@peptolab.com', 'Test'); $mail->setSubject( 'Demonstration - Sending Multiple Mails per SMTP Connection' ); $mail->setBodyText('...Your message here...'); // Manually control the connection $protocol->rset(); $mail->send($transport); } $protocol->quit(); $protocol->disconnect(); ]]>