Introduction | Zend_Mail Programmer's Reference Guide | Sending Multiple Mails per SMTP Connection
# Sending via SMTP To send mail via SMTP, Zend_Mail_Transport_Smtp needs to be created and registered with Zend_Mail before the send() method is called. For all remaining Zend_Mail::send() calls in the current script, the SMTP transport will then be used: Example #1 Sending E-Mail via SMTP $tr = new Zend_Mail_Transport_Smtp('mail.example.com'); Zend_Mail::setDefaultTransport($tr); The setDefaultTransport() method and the constructor of Zend_Mail_Transport_Smtp are not expensive. These two lines can be processed at script setup time (e.g., config.inc or similar) to configure the behavior of the Zend_Mail class for the rest of the script. This keeps configuration information out of the application logic - whether mail is sent via SMTP or » mail(), what mail server is used, etc.
Introduction | Zend_Mail Programmer's Reference Guide | Sending Multiple Mails per SMTP Connection