PC Ext: How External Sends Mail Between Postoffices (100826)



The information in this article applies to:

  • Microsoft Mail for PC Networks 3.2

This article was previously published under Q100826

SUMMARY

This article describes how the External Mail program (EXTERNAL.EXE) for version 3.2 of Microsoft Mail for PC Networks delivers mail between postoffices. This process involves several files in the Mail database.

MORE INFORMATION

The example shown below shows a typical file transfer of a single piece of mail from postoffice P: COMPANY/CORPORATE to Q: COMPANY/MAIL. First, External checks the postoffices for updates to user/group lists. These lists include all the new user lists and definitions that are defined in the postoffices through the Mail Administrator program (ADMIN.EXE).

Example

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

External then checks for any outgoing mail by opening and closing every external postoffice's KEY file. Flags within the files indicate if any mail is 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 files on P: COMPANY/CORPORATE. The filename in the example is 00000116.MAI.

The delivery by the External program is a two-part process called Dispatch and Mailer. The Dispatch program delivers the mail between the postoffices and the Mailer program processes the mail and places messages into recipients' mailbags.

Dispatch

NOTE: SESSION.LOG entries have been indented for reference.

The External program first reads the P2 file (00000116.MAI) from the CORPORATE postoffice and writes it to the MAIL postoffice (N:MAI\MA8\00000278.MAI).
   06-01-93 09:58 Transferring mail: mail file is: M:MAI\MA6\00000116.MAI.
   06-01-93 09:58 Sending P2...
   06-01-93 09:58 Target file: N:MAI\MA8\00000278.MAI
				
The Dispatch program 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.
   06-01-93 09:59 Sending P1...
   06-01-93 09:59 Target file: N:P1\00000278.P1
				
The External program then writes to the INQUEUE3.KEY and INQUEUE3.MBG files the name of the file in the P1 subdirectory that contains the recipients of the mail.

This concludes the delivery of the mail.
   06-01-93 09:59 P1 file successfully sent.
   06-01-93 09:59 Delivering new mail to NETWORK/MAIL.
				

Mailer

The Mailer program reads the INQUEUE3 files in the KEY and MBG subdirectory. The MBG queue contains the reference pointer (P1 subdirectory filename). The Mailer program 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.
   06-01-93 09:59 Processing received mail queue at: N: NETWORK/MAIL.
   06-01-93 09:59 INQUEUE file: N:MAI\MA8\00000278.MAI
   06-01-93 09:59 Delivering of mail from INQUEUE3 is complete.
   06-01-93 09:59 Delivering new mail to NETWORK/MAIL.
				
NOTE: A mail item that is sent to numerous people will contain a reference pointer for each person who is to receive the mail item; however, there will only be ONE .MAI file.
   06-01-93 09:58 Sending mail (1)
   06-01-93 09:58 From: NETWORK/CORPORATE
   06-01-93 09:58 To: NETWORK/MAIL
   06-01-93 09:58 Transferring mail: mail file is: M:MAI\MA6\00000116.MAI.
   06-01-93 09:58 Sending P2...
   06-01-93 09:58 Target file: N:MAI\MA8\00000278.MAI
   06-01-93 09:59 Sending P1...
   06-01-93 09:59 Target file: N:P1\00000278.P1
   06-01-93 09:59 P1 file successfully sent.
   06-01-93 09:59 Delivering new mail to NETWORK/MAIL.
   06-01-93 09:59 Processing received mail queue at: N: NETWORK/MAIL.
   06-01-93 09:59 INQUEUE file: N:MAI\MA8\00000278.MAI
   06-01-93 09:59 Delivering of mail from INQUEUE3 is complete.
   06-01-93 09:59 Delivering new mail to NETWORK/MAIL.
   06-01-93 09:59 N: NETWORK/MAIL: Checking for dispatch mail...
   06-01-93 09:59 No mail.
   06-01-93 09:59 Delivering new mail to NETWORK/CORPORATE.
   06-01-93 09:59 Delivering new mail to NETWORK/CORPORATE.
   06-01-93 09:59 Delivering new mail to NETWORK/MAIL.
   06-01-93 09:59 Delivering new mail to NETWORK/MAIL.
				

Glossary

   Term        Description
   ----        -----------

   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 equates to selecting a message from
               the Inbox and reading its 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
               equates to looking at the Inbox in the Mail program.

   P2          Another name for the .MAI file; also known as the
               contents of the message. This equates to 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.
				

Modification Type:MinorLast Reviewed:7/15/2004
Keywords:KB100826