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Q107767: PC Gen: How Global Groups Work When Sending Mail

Article: Q107767
Product(s): Microsoft Mail For PC Networks
Version(s): WINDOWS:2.1x,3.0,3.0a,3.2
Operating System(s): 
Keyword(s): 
Last Modified: 31-OCT-1999

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The information in this article applies to:

- Microsoft Mail for PC Networks, versions 2.1x, 3.0, 3.0a, 3.2 
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SUMMARY
=======

Versions 2.1, 3.0, 3.0a, and 3.2 of Microsoft Mail for PC Networks have a very
complex group structure. The global group definitions span many files. These
files include:

  GROUP.GLB (Contains the postoffice group names)
  GRPMEM.GLB (Used for group folders.)
  ADMIN.GRP (Contains tuple identifier (TID) values for group members)
  ADMINSHD.GRP (Shadow file of ADMIN.GRP)
  xxxxxxxx.MEM (Contains group member mailbags for external mail delivery)
  ADMIN.NME (Postoffice address list)
  ADMINSHD.NME (Shadow file of ADMIN.NME)

In addition, ACCESS2.GLB is used to find all local postoffice group member's
mailbag numbers, and NETPO.GLB is used when there are any external addresses
included in the global group. All external users or groups that are going to be
included in a local global group must be added to the postoffice address list
(ADMIN.NME) prior to being included in a local global group.

The files that are accessed when mailing to a global group from the postoffice
address list are:

  ADMIN.NME
  ADMIN.GRP
  GROUP.GLB and
  ACCESS2.GLB.

The NETPO.GLB will also be accessed if the group contains external addresses.

The GROUP.GLB appears to be an unnecessary component of the mailing process but
if the GROUP.GLB file is missing or if the GROUP.GLB has been reset to a 4 byte
header, then the user will receive a Notice 8," Error in transmitting mail or
server disk is full." However, if the group's definition in the GROUP.GLB has a
corrupted alias, address, TID (MEM filename), type, or delete flag, the group
can still be mailed to from the postoffice address list.

The ADMIN.NME has a 45 byte record that contains the group's alias, TID (which
for the group is the *.MEM filename), alias type (4 = group), and a pointer that
is a byte offset into the ADMIN.GRP file where the group's definition begins.
Each of the local user's addresses are also stored in the ADMIN.NME.

The ADMIN.GRP is a linked list of TID values representing all of the group
member's TID values in the ADMIN.NME. The byte offset stored in the group's
ADMIN.NME record points to the first member's record in the ADMIN.GRP which
contains that user's TID value in the ADMIN.NME and the byte offset from the
beginning of the ADMIN.GRP to the next member of the group. This linked list
continues until a null offset (0) is encountered, which is the end of the group
definition. The ADMIN.GRP contains all of the linked lists for all local global
group members on the postoffice.

Each group member's TID value in the ADMIN.GRP corresponds to that member's TID
value in the ADMIN.NME. Each of the local group member's mailbag numbers are
then derived from the user[ASCII 146]s ADMIN.NME record that points to the
user[ASCII 146]s record in the ACCESS2.GLB. The ACCESS2.GLB record contains the
filename of that user's mailbag.

The external groups or users that may have been added to the postoffice address
list in order to be included in the local group will have an alias type of 2.
All group members that have this alias type in the ADMIN.NME will have their
addresses resolved through the NETPO.GLB file. The external member's byte offset
in the NETPO.GLB file will be determined from the "file pointer" field in the
ADMIN.NME. The external member's record in the NETPO.GLB will then yield that
member's network name, postoffice name, mailbox name, and the mailbag number for
the external postoffice definition on the local postoffice. That member's mail
message will then be passed to the external postoffice's mailbag where it will
wait for the external MTA to send the message.

MORE INFORMATION
================

The following diagram may be helpful in conceptualizing the way groups are
resolved.

         Byte                               TID
        Offset           TID               /---->ACCESS2.GLB --->mailbag
                                         / 
ADMIN.NME------>ADMIN.GRP----->ADMIN.NME/ 
                                       \ 
                                         \  Byte Offset
                                           \---->NETPO.GLB ----->mailbag
                                             (external users only)

NOTE: The GROUP.GLB file must be present for the group mail to be resolved, but
it does not participate in determining the destination mailbags.

Additional query words: 2.1x 3.00 3.00a 3.20

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Keywords          :  
Technology        : kbMailSearch kbZNotKeyword3 kbMailPCN320 kbMailPCN300 kbMailPCN300a kbMailPCN21xSearch
Version           : WINDOWS:2.1x,3.0,3.0a,3.2

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