Caution: The documentation you are viewing is
for an older version of Zend Framework.
You can find the documentation of the current version at:
https://docs.zendframework.com/
SMTP Authentication - Zend_Mail
Zend_Mail supports the use of SMTP authentication, which can be enabled be passing the 'auth' parameter to the configuration array in the Zend_Mail_Transport_Smtp constructor. The available built-in authentication methods are PLAIN, LOGIN and CRAM-MD5 which all expect a 'username' and 'password' value in the configuration array.
Example #1 Enabling authentication within Zend_Mail_Transport_Smtp
Note: Authentication types
The authentication type is case-insensitive but has no punctuation. E.g. to use CRAM-MD5 you would pass 'auth' => 'crammd5' in the Zend_Mail_Transport_Smtp constructor.