Try to use Gmail smtp server (Google APPS) to send out email. I have read the related forum threads to use:
Imports Rebex.Net
Imports Rebex.Mail
Imports Rebex.Mime.Headers
smtp.Connect("smtp.gmail.com", 587, Nothing, SmtpSecurity.Explicit)
smtp.Login(myuseraccount, mypassword")
However, Error message occurred : Unable to perform revocation check of the server certificate.
By the way, I am using 2012R2 component in .NET 2.0