Query Regarding SMTP Authentication

Sir,

Can any one please tell me abt SMTP authentication.. how to get the
encryption code.. or how to do the authentication..?

also how to find the server, whether it need authentiation or not...?

and what authentication mechanism it follows.. ?

only with user's mailID and server name can we do authentication...???

any global SMTP server is available..??, so that we can test our application
from  my PC..???

please answer for these questions..

thanks in advance,
Vijayan.