🚀 go-pugleaf

In article <19960414.747A1D0.1341C@contessa.phone.net>, Mike Meyer writes:

> POP is a Post Office Protocol. A host in the SMTP peer network acts
> like a post office - it collects mail from other SMTP hosts on the
> internet and holds it until the POP client comes to collect it.
> Likewise, it will accept mail from POP clients for delivery elsewhere
> on the internet. Since POP was designed for use in hostile
> environments (your local university network, for instance) it includes
> user identification and authorization features. POP (2; I haven't
> checked 3) always depend on talking to an intermediate host that is
> filling the role of the Post Office to deliver mail. From the above,
> it appears that POP3 can deal with multiple mail servers and use any
> of them as the gateway if required.

Most POP clients send mail via SMTP.  So, when comparing SMTP to POP it
really only makes sense to compare the methods of receiving mail.

In a perfect world, SMTP always wins.  Mail comes and goes as quickly as
it possibly can.  Packets are only transmitted or received when mail is
transmited and received.

In our less perfect world, the environment neccessary to support SMTP
reception (DNS entries, fixed IP, sendmail or equiv, 24 hour uptime) are a
bit excessive when done on a per user basis.  POP goes a long way toward
doing away with these problems.  On the minus side, mail delivery is only
as fast as your polling interval.  And the more you poll, the more network
bandwidth and host resources you use.

If you don't have a full time connection, SMTP is not an option.  POP
still works, albeit not as well as with a full time connection.  The cost
of polling goes way up since it means bringing the link up.  Most people
just poll manually or only when the link is already up.

UUCP is an alternative for dial up connections.  It makes the most
effecient use of the link.  Further, it supposed to be possible to set up
"demand" connections.  This would get you just-in-time mail delivery
almost as good as SMTP.  Unfortunately, UUCP configuration is even worse
than SMTP and it is getting harder and harder to find ISP's with the
expertese to set up *their* end.

An intruiging future prospect is SMTP with bi-directional dial up ISDN. 
Bring up the link only when there is data to transmit.  Drop the link when
it goes quiet.  Configuration complexity is worse than SMTP and perhaps
worse than UUCP.  However, it would allow very fast just-in-time delivery
without the need for a leased line.

----
"You get more with a kind word and a 2x4 then with a kind word alone"
Remember the home hobbyist computer: Born 1975, died April 29, 1994