you may looking for :
resources.mail.transport.register = true ; True by default
full example : if you were in production you would use the first transport and in the development you would use development , pretty easy isn't
[production]
resources.mail.transport.type = smtp
resources.mail.transport.host = "smtp.example.com"
resources.mail.transport.auth = login
resources.mail.transport.username = myUsername
resources.mail.transport.password = myPassword
resources.mail.transport.register = true ; True by default
resources.mail.defaultFrom.email = [email protected]
resources.mail.defaultFrom.name = "John Doe"
resources.mail.defaultReplyTo.email = [email protected]
resources.mail.defaultReplyTo.name = "Jane Doe"
[development]
resources.mail.transport.type = smtp
resources.mail.transport.host = "smtp2.example.com"
resources.mail.transport.auth = login2
resources.mail.transport.username = myUsername
resources.mail.transport.password = myPassword
resources.mail.transport.register = true ; True by default
resources.mail.defaultFrom.email = [email protected]
resources.mail.defaultFrom.name = "John Doe"
resources.mail.defaultReplyTo.email = [email protected]
resources.mail.defaultReplyTo.name = "Jane Doe"
source : http://framework.zend.com/manual/en/zend.application.available-resources.html