The SMTP component is used to send Internet mail using the SMTP protocol (the Internet mail standard). The SMTP component implements a standard SMTP client as specified in RFC 821. It has a simple plug-and-play interface. It contains a number of properties like SendTo, Subject, From, Cc, BCc, etc. that map directly to the internet mail message headers with the same name (RFC 822).
The SMTPS component is used to send Internet mail using the SMTP protocol (the Internet mail standard). The SMTPS component is the SSL-enabled equivalent (RFC 2487) of the IP*Works! SMTP component. The main difference is the introduction of a set of new configuration settings, properties and events that deal with SSL security. The SSLProvider configuration setting chooses a security provider subsystem.
E-Mail Expert is an ActiveX COM DLL for sending SMTP and MIME email messages. E-Mail Expert works with VB, ASP, .NET and all languages that trap ActiveX DLL events. E-Mail Expert was designed to be easy to use, yet not restrict developers that have an advanced understanding of email, SMTP, MIME or Winsock.