Download VPOP3 User Guide - Paul Smith Computer Services

VPOP3 – Your email post office
POP3 Protocol
POP3 (Post Office Protocol Version 3) was created for dial-up Internet accounts
because of the limitations with the SMTP protocol. When collecting mail from an
ISP using POP3, the ‘client’ is the PC at the user’s end, and it is in total control of
what messages it receives and which ones it doesn’t.
The POP3 client can also typically view message headers without downloading
the entire message, see the message size before downloading it, delete messages
without downloading them, or leave messages on the server after downloading
them. Because of these POP3 facilities, VPOP3 can do a lot more to help you.
One of the normal problems which occurs if multiple email addresses are
directed to a single POP3 mailbox is that the SMTP Envelope (see above) is lost
when the message is placed in the mailbox. This means that the explicit message
routing information is lost, and all that VPOP3 has to go on is the data in the
message headers (eg To, Cc etc). This can cause problems if you receive messages
from mailing lists or which include Bccs. Some ISPs get around these problems
by extending the POP3 protocol (eg Demon Internet Services do this) or adding
special message header fields which VPOP3 can use if you tell it about them.
Page 172
User Manual
v 1.3.0 May 1999