The TPopSession object provides a simple, high-level interface for
accessing a POP3 mailbox, user authentication via USER/PASS or APOP protocols,
querying of server capabilities, mailbox status and message
information, downloading messages, and deleting them from the server.
The TSmtpSession object is a high-level wrapper around LibESMTP,
which allows programmers to easily send multiple emails in a single
login session, send emails to multiple recipients, add multiple
attachments to messages, all with just a few lines of code.