>In general, there's no guarantee that mail will arrive in the order
>that it was sent or be processed by LISTSERV in the order it was
>received.  So it's not good to depend on that.

Maybe, I did not explain clearly enough what I have done. Therefore,
I will describe my test in more detail. I have sent the following commands
in *one* single message to our local [log in to unmask]:

get sigi-l (header
unlock sigi-l
get sigi-l (header
unlock sigi-l
get sigi-l (header
unlock sigi-l
get sigi-l (header
unlock sigi-l
get sigi-l (header
unlock sigi-l
get sigi-l (header
unlock sigi-l
get sigi-l (header
unlock sigi-l
get sigi-l (header
unlock sigi-l

The result which was sent by LISTSERV is interesting...

---

From MAILER-DAEMON Wed Feb 02 20:10:42 2000
Return-path: <>
Envelope-to: [log in to unmask]
Delivery-date: Wed, 02 Feb 2000 20:10:42 +0100
Received: from mailgate.rz.uni-karlsruhe.de (mailgate.rz.uni-karlsruhe.de [129.13.64.97])
        by mailhost.rz.uni-karlsruhe.de with esmtp (Exim 3.02 #1)
        id 12G5Ai-0005oD-00; Wed, 02 Feb 2000 20:10:36 +0100
Received: from uni-karlsruhe.de ([log in to unmask] [129.13.64.210])
        by mailgate.rz.uni-karlsruhe.de with esmtp (Exim 3.02 #2)
        id 12G5AD-0006CL-08; Wed, 02 Feb 2000 20:10:05 +0100
Date:         Wed, 2 Feb 2000 20:10:05 +0100
From:         "L-Soft list server at Universitaet Karlsruhe (1.8d)"
              <[log in to unmask]>
Subject:      Re: lock
To:           LISTSERV Administrator <[log in to unmask]>
Message-Id: <[log in to unmask]>
Status: RO

> get sigi-l (header
File "SIGI-L LIST" has been mailed to you under separate cover.

The SIGI-L list has been locked. Do not attempt to add recipients "on the
fly" when you  send back the header;  if you want to make  changes to the
recipients list, you must use the regular GET command.

> unlock sigi-l
The SIGI-L list has been unlocked. It had been locked since 100/02/0 20:10
by LISTSERV Administrator <[log in to unmask]>.

> get sigi-l (header
File "SIGI-L LIST" has been mailed to you under separate cover.

The SIGI-L list has been locked. Do not attempt to add recipients "on the
fly" when you  send back the header;  if you want to make  changes to the
recipients list, you must use the regular GET command.

> unlock sigi-l
The SIGI-L list is not locked.

> get sigi-l (header
File "SIGI-L LIST" has been mailed to you under separate cover.

The SIGI-L list has been locked. Do not attempt to add recipients "on the
fly" when you  send back the header;  if you want to make  changes to the
recipients list, you must use the regular GET command.

> unlock sigi-l
The SIGI-L list is not locked.

> get sigi-l (header
File "SIGI-L LIST" has been mailed to you under separate cover.

The SIGI-L list has been locked. Do not attempt to add recipients "on the
fly" when you  send back the header;  if you want to make  changes to the
recipients list, you must use the regular GET command.

> unlock sigi-l
The SIGI-L list is not locked.

> get sigi-l (header
File "SIGI-L LIST" has been mailed to you under separate cover.

The SIGI-L list has been locked. Do not attempt to add recipients "on the
fly" when you  send back the header;  if you want to make  changes to the
recipients list, you must use the regular GET command.

> unlock sigi-l
The SIGI-L list is not locked.

> get sigi-l (header
File "SIGI-L LIST" has been mailed to you under separate cover.

The SIGI-L list has been locked. Do not attempt to add recipients "on the
fly" when you  send back the header;  if you want to make  changes to the
recipients list, you must use the regular GET command.

> unlock sigi-l
The SIGI-L list is not locked.

> get sigi-l (header
File "SIGI-L LIST" has been mailed to you under separate cover.

The SIGI-L list has been locked. Do not attempt to add recipients "on the
fly" when you  send back the header;  if you want to make  changes to the
recipients list, you must use the regular GET command.

> unlock sigi-l
The SIGI-L list is not locked.

> get sigi-l (header
File "SIGI-L LIST" has been mailed to you under separate cover.

The SIGI-L list has been locked. Do not attempt to add recipients "on the
fly" when you  send back the header;  if you want to make  changes to the
recipients list, you must use the regular GET command.

> unlock sigi-l
The SIGI-L list is not locked.

Summary of resource utilization
-------------------------------
 CPU time:        0.120 sec
 Overhead CPU:    0.120 sec
 CPU model:    9000/871
 Job origin:      [log in to unmask]

---

I performed this test in a similar way with three lists on *three* different
LISTSERVs:

   LISTSERV 1.8d on OpenVMS V7.1-1H2 (list AMALGAM)

   LISTSERV 1.8d on Windows NT 4.0   (list LYME-L)

   LISTSERV 1.8d on HP-UX B.10.20    (list SIGI-L on our local LISTSERV)

Only our local LISTSERV on HP-UX B.10.20 showed this strange synchronization
problem.

Siegfried