No, Power Messenger canot be used with an SMTP server that requires authentication.
Power Messenger uses the php mail() function to connection to the SMTP Server, the mail() function is not capable of passing authentication to the server.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.