Notification Step in NWBPM

Hi Experts,

I need to send emails to users and for that i am suing Notification step in NWBPM. And i assigned the user to Principles in the To tab of notification step properties and also provided the subject & content in the mail tab.

The email needs to be sent to lotus notes where in UME the mail id is maintained  for the User.

Do i need to do any other settings in order to trigger the mail.

Is SMTP configurations settings need to be done.

I am working on SAP PO 7.31 SP8 verison.

Kindly advise.

Thanks & regards

Narayanareddy B