PC Ext: How External Sends Mail Between Postoffices

ID: Q77628

The information in this article applies to:

Microsoft Mail for PC Networks, versions 2.1, 3.0, 3.0a, 3.2, 3.2a, 3.5

SUMMARY

In Microsoft Mail for PC Networks, it is useful to understand how the External Mail program (EXTERNAL.EXE) delivers mail between postoffices. This process involves several files in the mail system database.

MORE INFORMATION

The sample shown below shows a typical file transfer of a single piece of mail from postoffice P: MICROSOFT/CORPORATE to Q: MICROSOFT/MAIL. External first checks the postoffices for updates to user/group lists. These lists include all the new user lists and definitions that are programmed into the postoffices through the Administrator program (ADMIN.EXE).

A user has composed a message on postoffice MICROSOFT/CORPORATE and has addressed the message to a user on MICROSOFT/MAIL. The message is written into the database for MICROSOFT/CORPORATE in the KEY, MBG, and MAI subdirectories. If an attachment is included, a file is written to an ATT subdirectory.

External then checks for any outgoing mail by opening and closing every MBG and KEY file on the postoffice. Flags within the files indicate if there is any mail required to be sent.

In this example, one mail item is going to be sent from CORPORATE to MAIL. First, External reads the KEY, MBG, and MAI file on P: MICROSOFT/CORPORATE. The filename in the example is 00003D90.MAI.

The delivery by the External program is a two-part process called Dispatch and Mailer. Dispatch is used to deliver the mail between the postoffices and Mailer is used to process the mail and place messages into recipients' mailbags.

Dispatch

External first reads the P2 file (00003D90.MAI) from the CORPORATE postoffice and writes to the MAIL postoffice (Q:MAI\MAB\000003CB.MAI):


   [16:24] - Mail file: P:MAI\MA0\00003D90.MAI
   [16:24] - Sending P2...
   [16:24] - Target file: Q:MAI\MAB\000003CB.MAI

The dispatcher then writes to the P1 subdirectory the envelope of the mail message. The envelope contains a list of all the people to whom the mail message must be delivered. This includes the TO field and the CC field:


   [16:24] - Target file: Q:P1\000003CB.P1

External then writes to INQUEUE.KEY and INQUEUE.MBG the name of the file in the P1 subdirectory that contains the recipients of the mail.

This concludes the delivery of the mail:


   [16:24] - FM_SEND, ok

Mailer

Mailer reads the INQUEUE files in the KEY and MBG subdirectories. The MBG queue contains the reference pointer (P1 subdirectory filename). MAILER then reads the references contained in the file in the P1 subdirectory and writes to each recipient's KEY file and MBG file a pointer to the mail item contained in the MAI subdirectory:


   [16:24] - inqueue opened
   [16:24] - Processing received mail queue on: Q: MICROSOFT/MAIL
   [16:24] - Inqueue file: Q:MAI\MAB\000003CB.MAI

Note: A mail item that is sent to numerous people will have a reference pointer for each person who is to have the mail item but there will only be ONE .MAI file.


   [16:24] - Checking, P: MICROSOFT/CORPORATE, for list update...
   [16:24] -
   [16:24] - Checking, Q: MICROSOFT/MAIL, for list update...
   [16:24] -
   [16:24] - Sending mail (1)
   [16:24] -   From: MICROSOFT/CORPORATE
   [16:24] -     To: MICROSOFT/MAIL
   [16:24] - Mail file: P:MAI\MA0\00003D90.MAI
   [16:24] - Sending P2...
   [16:24] - Target file: Q:MAI\MAB\000003CB.MAI
   [16:24] - Sending P1...
   [16:24] - Target file: Q:P1\000003CB.P1
   [16:24] - FM_SEND, ok
   [16:24] -
   [16:24] - inqueue opened
   [16:24] - Processing received mail queue on: Q: MICROSOFT/MAIL
   [16:24] - Inqueue file: Q:MAI\MAB\000003CB.MAI
   [16:24] -
   [16:24] - inqueue closed
   [16:24] - inqueue opened
   [16:24] - inqueue closed
   [16:24] - inqueue opened
   [16:24] - inqueue closed
   [16:26] - inqueue opened
   [16:26] - inqueue closed
   [16:26] - inqueue opened
   [16:26] - inqueue closed
   [16:27] - Checking, Q: MICROSOFT/MAIL, for list update...
   [16:27] -
   [16:27] - Checking, P: MICROSOFT/CORPORATE, for list update...
   [16:27] -

Glossary


   Term       Definition
   -------------------------------------------------------------------

   ATT        Attachments subdirectory and attachments files.
              Referenced by a pointer within the message contents (MAI
              file).

   Contents   Contents of the message include the items such as the
              date, time, subject, priority, attachments, and the
              message itself. Another name for the MAI file. In visual
              terms this can equate to selecting a message from the
              Inbox and reading the contents.

   Envelope   See P1.

   MAI        See CONTENTS.

   MBG, KEY   Combined, these two files are used to provide a list of
              Inbox items that point to the mail message. This can
              equate to looking at the Inbox in the Mail program.

   P2         Another name for the MAI file. Otherwise known as the
              contents of the message. To equate, this would be the
              actual message that was composed.

   P1         An acronym for the addressing or the envelope of the
              message. The envelope contains all the TO and CC
              addresses the mail items are supposed to go to.

REFERENCES

SESSION.LOG was created with the following External command line:


   external -dpq -v -l -q1

Additional query words: 2.10 3.00 3.00a 3.20 3.20a 3.50

Keywords :
Version : WINDOWS:2.1,3.0,3.0a,3.2,3.2a,3.5
Platform : WINDOWS
Issue type :