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- Path: senator-bedfellow.mit.edu!bloom-beacon.mit.edu!usc!cs.utexas.edu!uunet!psinntp!newstand.syr.edu!arachnids.syr.edu!jmwobus
- From: jmwobus@mailbox.syr.edu (John Wobus)
- Subject: LAN Mail Protocols Summary
- Message-ID: <1993Nov4.081447.18969@newstand.syr.edu>
- Followup-To: poster
- Originator: jmwobus@arachnids.syr.edu
- Reply-To: jmwobus@mailbox.syr.edu
- Organization: Syracuse University, Syracuse, NY
- Date: Thu, 4 Nov 93 08:14:47 EST
- Approved: jmwobus@mailbox.syr.edu
- Lines: 301
- Xref: senator-bedfellow.mit.edu comp.mail.misc:14782 news.answers:14290
-
- Archive-name: LANs/mail-protocols
-
- Serving PCs and Workstations Using a Central Mail Server on an Internet
- ------- --- --- ------------ ----- - ------- ---- ------ -- -- --------
-
- (Note: this message is prepared by John Wobus of Syracuse University,
- jmwobus@mailbox.syr.edu who welcomes updates and corrections; this
- memo has not been checked very carefully and requires a lot of
- correction at this time. The last update was made 11/2/93).
-
- There are advantages to collecting mail destined to PCs and
- workstations on a central server, to be turned over to the PC or
- workstation on demand:
-
- - Your PC or workstation may be down quite a bit and less network
- bandwidth and less of the processing resouces of the sending computer
- are used if the computer receiving your mail is ready.
- - Some people use more than one PC or workstation to read mail.
- - A PC or workstation may not have the resources to store all the mail
- you receive.
- - It can make your e-mail address more like other users'.
-
- The easiest way to "implement" this is to run the central mail server
- like any multi-user system: let people sign on to it and use some mail
- utility. Then PC and workstation users can use "terminal sessions" to
- sign on to the central mail server and read their mail. This has the
- disadvantage of making the PC and workstation users learn and use the
- central mail server's procedures.
-
- SMTP, the "internet" mail protocol used to deliver mail between
- multi-user systems only supports mail transfer initiated by the
- sender. Other protocols have been devised to allow a workstation or PC
- to request transfer of mail, thus able to make use of a cnetral
- server. These include the published protocols POP (probably not used
- anymore), POP2, POP3, IMAP2, IMAP3 and DMSP.
-
- POP, POP2, POP3: These are rather minimal and are designed to be so.
- The three are similar but not enough alike to be interoperable. They
- are basically designed to identify the user by username and password,
- to transfer the mail from server to PC or workstation and to delete the
- mail transferred. It is assumed that SMTP will be used to send mail.
- Messages can be retrieved individually, but the only information you
- can get about a message without transferring it is its length in
- bytes-- useful for PCs with limited storage.
-
- POP2 and POP3 are still used a good deal. POP3 has a couple of
- optional extensions: one to avoid sending passwords, and one to aid in
- reading bulletin boards.
-
- IMAP2, IMAP3: The IMAP family is similar to the POP family, but also
- gives clients a way to do string searches through mail that still
- resides on the server. This is designed to allow the PC or workstation
- to be more selective as to which mail will be transferred. The POP
- protocols, on the other hand, are designed for simpler server
- software.
-
- IMAP2 is used quite a bit. IMAP3 is an incompatible offshoot that has
- not been implemented much. Recent work not yet documented in an RFC
- has extended IMAP2 to include support for multimedia mail.
-
- DMSP (aka PCMAIL): PCs and workstations can use this protocol to both
- send and receive mail. The system is designed around the idea that
- each user can own more than one workstation; however, the system
- doesn't seem to handle the idea of a "public workstation" very well.
- The PCs and workstations are assumed to hold state information about
- the mail, a directory so to speak, and when the PC or workstation is
- connected to the server, this directory is updated to "reality".
-
- Issue of Remote Access: Modern commercial e-mail packages typically
- have features designed to assist in remote access of ones e-mail.
- Features include:
- -ability to download mail through a modem
- -ability to synchronize two different systems which you are using to
- read your e-mail by plugging them together.
- Any method of reading e-mail using PCs or Macintoshes can be used
- remotely via the "PCanywhere(tm)" method, e.g. by dialing up your own
- office PC and using one of the several kinds of software that allow you
- to control your PC over the phone. Also, any LAN-based method can be
- used by using one of the several methods of providing the same protocol
- support over dialup lines as are on LANs (SLIP or PPP for the
- above-mentioned, TCP/IP-based protocols, ARA for Appletalk-based
- protocols, etc, and sometimes using two different protocols, one
- incapsulated in the other) under the constraint that any operations
- that use the network will be much slower. Also, POP3 is often used
- directly over modems (for example, Eudora can be used in this manner).
- The ideal protocol for remote access would not penalize the user for
- the much slower communications speed (usually slower by a factor of
- 100: note that a lot of LAN-based software was written without regard
- to minimizing the necessary communication, thus is really hurt by such
- slow speeds), yet would allow the same software to run both remotely
- and locally, with a wonderful user interface. It would also not be
- overly expensive in communications equipment or services. This is a
- difficult set of objectives and the above-three protocols can achieve
- some of them for some users, but what they actually achieve depends a
- lot on the user's pattern of e-mail usage. If a user reads just a
- small amount of mail, then we would not worry about the length of time
- necessary to download it remotely with POP3, but if the person receives
- a lot of mail, but just wants to read a small amount of it at home,
- then with IMAP2, they could pick and choose what to read, eliminating
- some download time. If someone is paying for the telephone line time
- (possibly the user if it is a long distance call; in any case, the
- institution pays a monthly fee for each line it offers, which is
- dependent upon how many users it is serving, how often they call, and
- how long their calls are) then IMAP2's natural method of usage which
- requires the phone call to remain while a user is reading, poking
- around, sending, and rearranging mail can be much more costly than
- using POP3 if one call is used to quickly download all the mail and
- another later call is used to send any replies. Thus with POP3 a user
- might have two 1 minute calls before and after a 30 minute e-mail
- session instead of keeping the call for 30 minutes with IMAP2, and each
- phone line the institution offers could be serving 15 times as many
- such users who would each pay a lot less in long-distance phone bills.
-
- More about the protocols:
-
- Name: Post Office Protocol, Version 2
- Nickname: POP2
- Document: RFC 937 (Butler et al, February 1985)
- TCP-port: 109
- Sites:
-
- Name: Post Office Portocol, Version 3
- Nickname: POP3
- Document: RFC 1460 (Rose, May 1993)
- TCP-port: 110 (109 also often used)
- Sites: UC Irvine, MIT
-
- Name: Distributed Mail Service Protocol
- Nickname: DMSP, Pcmail
- Document: RFC 1056 (Lambert, June 1988)
- TCP-port: 158
- Sites: MIT
-
- Name: Interactive Mail Access Protocol, Version 2
- Nickname: IMAP2
- Document: RFC 1176 (Crispin, August 1990)
- TCP-port: 143
- Sites: Stanford, U Washington
-
- Name: Interactive Mail Access Protocol, Version 2 bis
- Nickname: IMAP2bis
- Document: ?
- TCP-port: 143
- Sites: U Washington
-
- Name: Interactive Mail Access Protocol, Version 3
- Nickname: IMAP3
- Document: RFC 1203 (Rice, February 1991)
- TCP-port: 220
- Sites: Stanford
-
- Implementations:
-
- Prot Computer Implementation End Source
- ------ ----------- ------------------- ------- --------------------------------
- DMSP PC pc-epsilon (3.1) client allspice.lcs.mit.edu
- DMSP PC pc-netmail (3.1) client allspice.lcs.mit.edu
- DMSP PC pc-reader client allspice.lcs.mit.edu
- DMSP Unix Pcmail 3.1 reposit. server allspice.lcs.mit.edu
- DMSP Unix/EMACS Pcmail 4.2 client allspice.lcs.mit.edu
- DMSP PC PC/TCP client FTP Software
- DMSP OS/2 PC/TCP client FTP Software
- DMSP OS/2 TCP/2 client Essex Systems
- DMSP OS/2 TCP/2 SERVER PACK server Essex Systems
- DMSP OS/2 TCP/2 ADV CLIENT client Essex Systems
- IMAP2 Macintosh MacMS 2.2.1 client sumex-aim.stanford.edu 10/15/93
- IMAP2B Macintosh Mailstrom 1.04 client sumex-aim.stanford.edu 10/19/93
- IMAP2B Macintosh Mailstrom 2 (b?) client sumex-aim.stanford.edu 10/19/93
- POP2 Macintosh MacPOP 1.5 client trident.arc.nasa.gov
- POP2 MS-DOS PC POP 2.1 client trident.arc.nasa.gov
- POP3 Macintosh TCP/Connect II client InterCon Systems Corporation
- IMAP2 NeXT EasyMail client ftp.cac.washington.edu
- IMAP2 NeXT MailManager server ftp.cac.washington.edu
- IMAP2 TOPS20 ? server ?
- IMAP2 Unix imap kit server ftp.cac.washington.edu
- POP23 Unix imap kit server ftp.cac.washington.edu
- IMAP2 Unix Pine 3.07 client ftp.cac.washington.edu
- POP3 Macintosh Eudora 1.3.1 client ftp.qualcomm.com 11/2/93
- POP3 Macintosh Eudora 1.4 client ftp.qualcomm.com 11/2/93
- POP3 Macintosh Eudora 1.4.1 (beta) client ftp.qualcomm.com 11/2/93
- POP3m Macintosh Eudora 2.0 (in dev) client ?
- POP3 MS-WINwf Eudora 1.0.1 client ftp.qualcomm.com 9/21/93
- POP3 MS-WINw Eudora 1.4b17 client ftp.qualcomm.com 11/2/93
- POP3 MS-WINw Eudora 2.0a14 client ? 11/2/93
-
- IMAP2 Unix ? client ftp.cac.washington.edu
- IMAP2 Unix imapd 3.1 server sumex-aim.stanford.edu*
- IMAP2 Unix/X ximap 0.7.2 client sumex-aim.stanford.edu
- IMAP2 MS-DOSl+ PC-Pine (beta) client pine@cac.washington.edu
- IMAP2 Xrx Lsp Mch ? client ?
- IMAP2 MS-WIN ECS (beta) client ISA, ftp.srv.ualberta.ca
- POP2 Macintosh POPMail II client boombox.micro.umn.edu
- POP Macintosh POPMail II 2.09 client boombox? 9/21/93
- POP2 Macintosh POPMail II 2.09 client boombox? 9/21/93
- POP3 Macintosh POPMail II 2.09 client boombox? 9/21/93
- IMAP2 Macintosh POPMail II 2.09 client boombox? 9/21/93
- POP2 Macintosh MailStop server boombox.micro.umn.edu
- POP2 MS-DOS LifeLine Mail client SunSelect
- POP2 MS-DOSk ? server ucsd.edu
- POP2 MS-DOSk ? server boombox.micro.umn.edu
- POP3 MS-DOSk pop3serv server biochemistry.crwu.edu
- POP2 MS-DOS MD/DOS-IP client U Maryland
- POP2 MS-DOS PC/TCP client FTP Software
- POP2 OS/2 PC/TCP for OS/2 client FTP Software 11/2/93
- POP23 MS-DOSp POPmail/PC 3.0 client boombox.micro.umn.edu 11/2/93
- POP3 MS-DOS? Minuet (beta) client boombox.micro.unm.edu 11/2/93
- IMAP? MS-DOSp POPmail/PC 3.0 client boombox.micro.umn.edu
- POP? MS-WINls TCPMail client Pinesoft (pinesoft@net.com)
- POP2 Unix POPmail/unix server boombox.micro.umn.edu
- POP2 Unix popd (USC-ISI) server trident.arc.nasa.gov
- POP2 Unix imapd/ipop2d server ftp.cac.washington.edu
- POP23k Unix mh-6.7 (UCI RandMH) both ftp.cc.berkeley.edu
- POP? Unix zmail client Z-Code Software (info@z-code.com)
- POP23k UnixX xmh/mh client ?
- POP23k UnixX dxmail/mh client DEC
- POP2 VM FAL server IBM
- POP2 VM ? server Texas Tech University
- POP2 OS/2 TCP/2 SERVER PACK server Essex Systems
- POP2 VMS MULTINet server TGV, Inc.
- POP2 HP3000/MPE NetMail/3000 server 3K Associates
- POP3k Macintosh Eudora X client ftp.brown.edu
- POP3 Macintosh MacPOP (Berkeley) client ftp.cc.berkeley.edu
- POP3k Macintosh TechMail 2.0 client net-dist.mit.edu
- POP3 Macintosh MacMH client jessica.stanford.edu/info
- POP3 Macintosh POPMail II client boombox.micro.umn.edu
- POP3 Macintosh MailStop (soon) server UMinn
- POP3 Macintosh VersaTerm Link client Synergy Software 10/8/93
- POP3 Macintosh LeeMail 2.0.2 (shw) client chs.cusd.claremont.edu 10/12/93
- POP3t Unix popper-1.7 server ftp.cc.berkeley.edu 10/15/93
- POP3k Unix popper-1.7k server ftp.brown.edu
- POP3 Unix popper-1.831 server ?
- POP3 Solaris2.X popper-1.831 mod server ftp.uoregon.edu 10/19/93
- POP3k Unix mh-6.7 (UCI RandMH) both ics.uci.edu
- POP3 Unix imapd/ipop3d server ftp.cac.washington.edu
- POP3t MS-DOSnpo PC/TCP client FTP Software
- POP3 OS/2 PC/TCP for OS/2 client FTP Software 11/2/93
- POP3 MS-DOS TechMail(future) client ?
- POP3 MS-DOS ? client logos.ucs.indiana.edu
- POP3 MS-DOSp NuPOP 1.03 client ftp.acns.nwu.edu 10/26/93
- POP3 MS-DOSp NuPOP 2.00 (beta) client ftp.acns.nwu.edu 9/21/93
- POP3 MS-WIN Pceudora client ftp.qualcomm.com 9/24/93
- POP3 ? POPgate (Pmail gw) client risc.ua.edu 9/24/93
- POP3 MS-DOSl PMPOP (Pmail gw) client risc.ua.edu 10/20/93
- POP3x MS-WIN WinQVT (2.1) client QPC Software (shareware)
- POP3 MS-WINp wnqvtnet 3.0 client ftp.cica.indiana.edu
- POP3 MS-WIN Open Systems Mail client Pine Software
- POP3 VMS IUPOP3 (1.7) (1.6?) server logos.ucs.indiana.edu
- POP3 VMS MULTINet both TGV, Inc.
- POP? VMS PMDF 4.2 server Innosoft
- IMAP? VMS PMDF 4.2 server Innosoft
- POP3 OS/2 TCP/2 SERVER PACK server Essex Systems
- POP3 OS/2 TCP/2 ADV CLIENT client Essex Systems
- POP? MS-DOS UCDmail client ucdavis.ucdavis.edu
- POP? MS-DOS PC POP client ?Bill Schweickert/Sterling Fed
- POP? MS-WINnpo Super-TCP for Wndws client Frontier Technologies 10/26/93
- POP? MS-WIN Windows ELM client lister.cc.ic.ac.uk 11/2/93
- POP? MS-DOSni ChameleonNFS client NetManage
- POP? Macintosh MEWS client ?
- POP? Macintosh byupopmail client ?
- POP? VM ? server TTUVM1
- ? Macintosh Hypermail ? ?
- ------ ----------- ------------------- ------- --------------------------------
- Appendix:
- Some other packages for desktop systems
- ------ ----------- ------------------- ------- --------------------------------
- uucp Macintosh uAccess peer Intecom [12/17/92]
- SMTP Macintosh LeeMail 1.2.4 peer Shareware, laf@mitre.org
- SMTP Macintosh LeeMail 2.0.2 (shw) peer chs.cusd.claremont.edu 10/12/93
- SMTP MS-DOSni ChameleonNFS peel NetManage
- uucp Macintosh FernMail peer Shareware, dplatt@snulbug.mtview.ca.us
- prop Macintosh MacPost both ftp.lu.se 10/19/93
- uucp Macintosh Eudora 1.3.1 peer ftp.qualcomm.com
- uucp Macintosh UUPC peer dplatt@snulbug.mtview.ca.us
- uucp Macintosh gnuucp peer jim@fpr.com
- uucp MS-DOS waffle peer ?
- uucp MS-DOS UUPC peer ?
- ? MS-Windows Pegasus/Win 1.02 client risc.ua.edu 10/5/93
- ? MS-DOS Pegasus/DOS 3.01 client risc.ua.edu 10/5/93
- ? Macintosh Pegasus/Mac 2.04 client risc.ua.edu 10/5/93
- SMTP MS-DOS Charon gateway risc.ua.edu 10/15/93
- ------ ----------- ------------------- ------- --------------------------------
- Other issues:
- (1) What are the common extensions to POP3 and which clients/servers
- support them?
- POP3k - Kerberos
- POP3a - AFS Kerberos
- POP3x - ?
- POP3t - xtnd xmit facility--allows client to send mail through additional
- POP commands, thus allowing server to verify/log source of mail.
- (2) What DOS protocol stacks are supported?
- MS-DOSm - Lan Manager
- MS-DOSn - NDIS Drivers
- MS-DOSl - Lan Workplace for Dos
- MS-DOSs - Sun PCNFS
- MS-DOSp - Packet Drivers
- MS-DOSo - ODI Drivers
- MS-DOSi - IPXLink
- MS-DOSf - FTP Software PC/TCP
- MS-WIN? - similar
- MS-WINw - WinSock compliaint
- ------ ----------- ------------------- ------- --------------------------------
-