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NWG/RFC#469                             Michael D. Kudlick MDK (SRI-ARC)NIC 14798                               8-MAR-73                      Network Mail Meeting SummaryIntroduction   The purpose of this RFC is to briefly summarize, from the NIC's   viewpoint, the principal conclusions reached at the Network Mail   Meeting held Friday, February 23 1973, at SRI-ARC.      Please refer to RFC #475 (NIC 14919) for Abhay Bhushan's      comprehensive summary of the issues discussed at the meeting.      There is no major disagreement between the present RFC and RFC      #475.      RFC #453 (NIC 14317) contains background information on the      meeting.      RFC #479 (NIC 14948) describes what the NIC would like to see      included in the File Transfer Protocol for Network Mail purposes,      and also describes briefly how the NIC would use the information.   The present RFC is organized as follows:      Conclusions      Discussion      AttendeesConclusions   Additional FTP mail requirements were decided upon.  These would be   implemented as a new mail command, with the following subcommands:      TO         This field is explicitly allowed to contain multiple         addressees, with a standard syntax:  user@host.      FROM         This field provides a return-address for notification of         undeliverable mail, as well as a clearcut identification of the         sender for the recipient's information..                                                                [Page 1]

NIC 14798                                       MDK 8-MAR-73 17:24 14798      AUTHOR         This field denotes the author of the mail.  There may be         multiple authors      TITLE         The "title" (i.e. subject) of the mail is to be terminated by         period carriage return.      ACKNOWLEDEGMENT  success / failure (time out) / normal         For use by the intermediate host, probably the NIC in most         cases, to tell the sender what happened to his attempt to send         mail.  (Note:  "normal" wasn't defined.)      RECORDED  jnumber / null         Note: "jnumber" is the pre-assigned accession number (NIC         number), to be used when known.         The "RECORDED" subcommand provides for the option of having the         mail recorded.  Information given with this subcommand would be         recognized at the NIC. Options are:            to be recorded (in NIC journal) only,            to be recorded and distributed,            to be distributed only.         This field would also be used to inform the recipient that the         mail has been recorded.            (In retrospect, it may be preferable to have a separate            command to inform the recipient of this fact, but no            decision on this was made at the 23-Feb-73 meeting.)      TYPE  long / urgent / ordinary         This allows the recipient site to take whatever action it         thinks appropriate in storing the mail.      TEXT / FILE / CITATION         TEXT            This field is for the text of the mail message.                                                                [Page 2]

NIC 14798                                       MDK 8-MAR-73 17:24 14798      FILE         The purpose of the field is unclear to me.  Does it contain a         machine readable pointer to the file that the sender wishes the         recipient to read?      CITATION         This field is a person-readable pointer to the file that the         sender wishes the recipient to read.  When the citation command         is used, no mail is sent other than the citation.Discussion   Introduction      The key aspects in the solution are:         1) It is based on FTP.         2) It uses the NIC without requiring direct use of NLS.         3) There is a mechanism for uniformity in the use of         user identifications.         4) There is a mechanism for recording the mail for         later reference.      These issues are covered in the discussion that follows.New FTP Mail Subcommands   TO      Addressee Format         The standard form of the address is:  user@host         "User" may be an individual's last name; or it may be whatever         other identification the recipient has chosen AND has made         known to the rest of the network.            If the intended host doesn't recognize the intended            recipient's identification, then it sends back an            "undeliverable" mail message to the sender's host.  It is up            to the individual to keep the NIC informed of his wherabouts            [sic]; otherwise, he may not get his mail on time.                                                                [Page 3]

NIC 14798                                       MDK 8-MAR-73 17:24 14798      NIC Role         The NIC need have no role at all for mail sent from point A to         point B, whenever that mail is not to be recorded at the NIC.         For mail that is to be recorded at the NIC, the RECORDED         subcommand is to be used.         Also, when the sender does not know the standard address of the         recipients, he may use the NIC to obtain this information.      Idents and Addresses         The NIC will modify its identification files to include the         "user@host" standard address for each individual.            Sites may ask the NIC to translate from NIC Ident, or from a            user's last name, to the standard address.  A query facility            will be made available at the NIC to do the translation on            request.  The translation service will also be available for            "group idents".            This service would be FTP-like, in term of the prootocol            [sic] it accepts, but would not be within FTP itself.  A            different server process would handle Ident translation            requests.            Translation will also be done at the NIC when the NIC is            used as an intermediate point on the delivery route.               The NIC could be an intermediate point for recording the               mail as a NIC journal item, and for forwarding the mail               to its ultimate destinations.  During this process, the               NIC would translate from NIC idents to standard               addresses.      In the NIC ident files, provision already exists to specify      hardcopy or on-line delivery of recorded (NIC Journal) mail.            This provision will be extended to include a "network"            attribute, which means "deliver the mail to the host of this            person".            The network attribute may be qualified by restricting all            mail to be kept at the sender, with only a notification            message actually mailed.                                                                [Page 4]

NIC 14798                                       MDK 8-MAR-73 17:24 14798            Notification would be in the form of a citation giving "to",            "from", "title", "date of submission", and "location of            mail".      TIP Users         To enable TIP users to have access to the mail system, both for         sending and receiving mail, it was suggested that some hosts         will have to be the "home" site for these users (but no more         than one "home" site per user).         That is, an account that allows a TIP user to send and receive         mail will have to be established at such a host.            For the present, any TIP user can use the SRI-ARC system for            his mail requirements.         An alternate solution, that TIP's be equipped with a hardcopy         device that is continuously available for printing mail, was         discarded in favor of the above approach.   FROM      The "FROM" command in FTP, identifies the sender in "standard      address" form.         This will allow "undeliverable" mail notices to be sent back to         the originator.            The default condition is that the sender's host must retain            the mail until it is "delivered" to the recipient's host.               "Delivered"  means that the recipient's host has accepted               the mail. It does NOT mean that the recipient has READ               the mail.            Alternatively, the sender may designate that an intermediate            host store the mail.  Then the intermediate host has the            responsibility of storing the mail until it is "delivered"            to all intended recipients.         The "ACKNOWLEDGEMENT" command will allow an optional, positive         acknowledgement to be given to the originator of the mail (the         "FROM" addressee), stating that the mail was delivered.                                                                [Page 5]

NIC 14798                                       MDK 8-MAR-73 17:24 14798   AUTHOR      The AUTHOR may be several persons. For recorded documents the      authors appear separately in the index of authors, to facilitate      searching for mail when an author is known, but the title and      location of the mail are unknown.   TITLE      The TITLE field is especially useful for recorded mail, since      indexes on key words in the title can be produced relatively      easily, and facilitate searching for mail.      For this reason, the title should be a succinct indicator of the      contents.   ACKNOWLEDGEMENT      Acknowledgement of failure to deliver should be given to the      sender.         An optional, positive acknowledgement of successful delivery to         the recipient's sitename will be given on request of sender         (like U.S. CERTIFIED mail).         No acknowledgement that the recipient actually saw the mail         will be given (comparable to not having U.S. REGISTERED mail).   RECORDED      The concept of "recorded" mail is that a permanent record of the      mail is kept centrally, to allow future references and re-readings      of the mail to be made.         For example, in the NIC Journal system, a record is kept of all         the items entered into the Journal.  From this record, author,         title-word, and NIC number indexes are produced to allow for         references and re-readings.         The key to retrieval of recorded Journal items is the use of an         accession number (the NIC number).  This essentially removes         the possibility of duplicate filenames being used.      The basic aspect of recorded mail which was discussed at the mail      meeting is the assignment of an "accession" number.                                                                [Page 6]

NIC 14798                                       MDK 8-MAR-73 17:24 14798         It was decided to get the accession numbers from the NIC on an         as-needed basis, without pre-assignment and without local         assignment of numbers.         This subject may be reviewed in the future.  Local assignment         may be desirable to prevent the NIC from becoming a bottleneck         in the mail process.         It was pointed out that local assignment of numbers would be         un-ambiguous if the numbers included some information such as         sitename, date, and time.      One other problem exits [sic], namely "where is the recorded      document?".         Initially the document should be in the NIC, but ultimately it         could be anywhere on the Network, provided only that there is a         central mechanism for indexing and cataloging all the recorded         documents.         The pathname to the recorded document would then include         filename and sitename.   TYPE      The TYPE subcommand was a result of a discussion on the      problems of large mail files, and the associated      question of who would pay for the processing and storing      of these files.      The main decisions made were:         a) The processing, transmittal, and storage costs of         sending mail should be borne at the sender's host.         b) The processing and storage costs of receiving         mail should be borne at the recipient's host         initially, as a default.      Information to enable the recipient host to make an      intelligent decision about where to store the incoming      mail are passed along via the TYPE command.         The recipient host will have the local option of         providing either of the following services:                                                                [Page 7]

NIC 14798                                       MDK 8-MAR-73 17:24 14798            a) free use of system to send mail;            b) free use of system to receive mail, i.e. login            not required for delivery over the Network.  (A            possible alternative is use of a "mail" account,            or use of the recipient's account, for processing            and storage of the incoming mail.   TEXT / FILE / CITATION      TEXT         This field is for the text of the mail message.      FILE         The purpose of this field is unclear to me.  Does it contain a         machine readable pointer to the file that the sender wishes the         recipient to read?      CITATION         The citation is a person-readable pointer to the file that the         sender wishes the recipient to read.         An alternative to sending entire messages or files over the         Network is to use the "CITATION" mechanism. With this, the         sender sends a short message (the citation) saying, in effect,         "please read file X at site Y".            This alternative would be especially useful for            a) mail that is distributed with group idents (to all            liaisons, for example), and            b) "long" files (size not defined) that the recipient may            not be immediately interested in.            However no method of enforcing use of this alternative was            discussed.  It will be up to the recipients to devise a            scheme satisfactory to them.Other General Discussion   Bob Kahn placed on the floor the following question (I paraphrase):      Can't the design of a mail system be made to include alternative      sources of data and alternative modes of operation, unless      exclusion of these alternatives can be quantitatively defended?                                                                [Page 8]

NIC 14798                                       MDK 8-MAR-73 17:24 14798      Particular aspects of this question are:      1) What is the desirability and difficulty of admitting different      data sources into the mail system?         What are the "boundaries" that divide permitted from prohibited         data sources?         What is the quantitative distinction between deferred and         realtime mail?         Will the design we come up with allow such things as            a) handling a calendar that reflects the known and            anticipated whereabouts of people so that meetings can be            scheduled sensibly?            b) formatting the mail contents for later query and other            information handling?      2) Whatever primitives we implement, can't they be designed so as      not to preclude things like Tenex "linking"?         This requires two-way data communication paths.         How do we specify and get the attention of a "sink" for the         data stream?            e.g., for interprocess communication, and for Tenex-type            "linking".   The general reaction to this discussion was one of perspective:      In the scheme of things that could be considered "point-to-point      communication", mailbox-type of communication is not the most      general kind.      AKB listed several types of communication problems:         program-program communication         people-people real-time communication,  e.g.         Tenex-type "links"         computer teleconferencing         mailbox communication: cataloging, storage         protocols: host-host, telnet, file transfer                                                                [Page 9]

NIC 14798                                       MDK 8-MAR-73 17:24 14798      A design for a mailbox-type system won't be required to encompass      the problems of, say, a computer teleconferencing system, which      has attributes (real-time, video, very large volume of data to be      transferred, to name some) that are not attributes of a mail box      system.Attendees at the Network Mail Meeting 2/23/73 at SRI-ARC           Nancy Mimno             BBN   ACB     Alan Bomberger  AMES-67   AKB     Abhay Bhushan   MIT-DMOG   AWH     Wayne Hathaway  AMES-67   CHI     Charles Irby            SRI-ARC   DHC     Dave Crocker            UCLA-NMC   JBP     Jon Postel              UCLA-NMC   JDH     Dave Hopper             SRI-ARC   JEW     Jim White               SRI-ARC   LPD     Peter Deutsch           PARC-MAXC   MCK     Mark Krilanovich        UCSB-MOD75   MDK     Mike Kudlick            SRI-ARC   REK2    Bob Kahn                ARPA   RKK     Rajendra Kanodia        MIT-MULTICS   RST     Ray Tomlinson   BBN-TENEX         [ This RFC was put into machine readable form for entry ]         [ into the online RFC archives by Joseph Marshall 9/97  ]                                                               [Page 10]