Technical Library

E-Mail

Helpful Service Machines

What is POP3 Mail?

POP3 mail is a store and forward service. It resembles a Post Office Box in that the mail for your address is delivered and stored for you until you are ready to pick it up.

POP3 service provides an option for machines that lack one or more resources, such as an older workstation, diskless workstation, or an older computer.

A server with the resources accepts the incoming mail for a site. The server stores the mail in a mailbox for the POP3 client. The client connects to the server to retrieve mail on demand.

Remote Access service uses POP3 mail to deliver mail to Remote Access customers. However, outgoing mail uses Simple Mail Transfer Protocol (SMTP), since the user has a PPP connection.

POP3 mail requires SLIP (Serial Line IP) or PPP (Point-to-Point) TCP/IP access for connection to the Internet. This can be a dialup connection made by the POP3 client to a POP3 server used for e-mail and discussion groups.

Why use POP3 Mail?

POP3 mail is a solution for those who are unable to maintain a message transport system (MTS), but would like to send mail over the Internet.

POP3 mail is an alternative for those who do not have the resources to allow an SMTP server, as well as a local mail delivery system, to be kept continuously running. It may also be too expensive or impractical to maintain an Internet connection for long periods of time.

The POP3 Protocol

ASCII protocol, can be imitated by a terminal connection.

Client connects to port 110.

Sends commands to server:

• USER
  Client sends id.
• PASS
  Client sends password.
  Note: password is in lower case.
• LIST
  Client requests list of mail messages.
• RETR
  Client requests server to send message.
• DELE
  Client requests server to delete message.

Common Problems

I am unable to retrieve mail.

• Try to ping the server where your mail is stored. If no reply, the mail server may be down.
• Can you telnet to port 110 of the server? If not, the POP3 server may not be loaded.

My password is not working.

• Be sure that you use all lower case characters in the password.