Quick definitions

• SMTP

Simple Mail Transfer Protocol A protocol used to send e-mail on the Internet. SMTP is a set of rules regarding the interaction between a program sending e-mail and a program receiving e-mail.

• SMTPS

The same as SMTP with the addition of an extra SSL layer that encrypts the connection.

• POP3

Post Office Protocol 3. A protocol that provides a simple, standardized way for users to access mailboxes and download messages to their computers.

• POP3S

The same as POP3 but with a SSL layer that encrypts the connection.

• IMAP

Internet Message Access Protocol (sometimes listed as Internet Mail Access Protocol). A mail protocol that provides management of received messages on a remote server. The user can review headers, create or delete folders/mailboxes and messages, and search contents remotely without downloading. It includes more functions than the similar POP protocol.

• IMAPS

The same as IMAP but with a SSL layer that encrypts the connection.