Mail loops are considered poor netiquette because they annoy subscribers and may cause readers to unsubscribe. Also used by email publishers to make email addresses clickable in some email programs. This is usually to prevent spam or off-topic posts. PGP can be used for a variety of security tasks, including the ability to attach a digital signature to an email, which allows the recipient to verify the sender. Generally displayed with a fixed-width font, plain text is used to create HTML documents.
Plain text is also the most common type of data to be encrypted.
POP - Post Office Protocol. A protocol that an email client uses to communicate with an email server. PPP - A protocol that allows a computer to access the Internet via a telephone line and modem. Most list server software allows users to place their work inside of a holding area where it remains indefinitely until it has been moderated or approved. Rich media requires more bandwidth and storage space than ordinary text.