Stands for "Simple Mail Transfer Protocol." This is the protocol used for sending e-mail over the Internet. Your e-mail client (such as Outlook, Eudora, or Mac OS X Mail) uses SMTP to send a message to the mail server, and the mail server uses SMTP to relay that message to the correct receiving mail server. Basically, SMTP is a set of commands that authenticate and direct the transfer of electronic mail. When configuring the settings for your e-mail program, you usually need to set the SMTP server to your local Internet Service Provider’s SMTP settings (i.e. "smtp.yourisp.com"). However, the incoming mail server (IMAP or POP3) should be set to your mail account’s server (i.e. hotmail.com), which may be different than the SMTP server.
As the name implies, this is software that "spies" on your computer. Nobody likes to be spied on, and your computer doesn’t like it either. Spyware can capture information like Web browsing habits, e-mail messages, usernames and passwords, and credit card information.