X400: Unable to Send or Receive Mail (124737)

SYMPTOMS

Version 3.2 of Microsoft Mail Gateway to X.400 may disconnect an existing session under heavy use conditions or it may be unable to establish outgoing or incoming connections, and it may display one or all of the following errors:

ERROR 3 (RTS): RTS open refused (Session limit exceeded)

DEBUG (T4_recv): Connection xx: tp_wait() failed:15

DEBUG (T4_send): Connection xx: tp_accept() failed:1

CAUSE

If the gateway is under heavy use, two errors may occur as it counts the number of active connections:

This count is incorrectly decremented with every occurrence of a connection request on the listening connection. This is incorrect; the listening connection is not an active connection. Eventually, the count will decrement to zero (0), and if a connection is active, it will be closed.
Every attempted connection used additional memory in RAM. The previous connection attempt was not being cleared from memory. The lack of memory results in the "tp-wait" errors. The "tp_accept" errors tell the sending MTA that the gateway cannot accept incoming connections at that time.

For additional information, please see the following article in the Microsoft Knowledge Base:

119303 X400: Err Msg: ERROR 3 (RTS): RTS Open Refused...

RESOLUTION

A supported fix that corrects this problem is now available from Microsoft, but has not been fully regression tested and should be applied only to systems experiencing this specific problem.

To resolve this problem, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

The English version of this fix should have the following file attributes or later:

   File Name      Version
   ----------------------
   X400gate.exe   3.2.12

This hotfix has been posted to the following Internet location as X400gy2k.exe:

ftp://ftp.microsoft.com/bussys/mail/gateways-public/All-Y2K/

MORE INFORMATION

The updated X400GATE.EXE file includes the following modifications for the causes listed above:

The count is no longer decremented unless an active connection is released.
The TP4 stack is deactivated and reactivated with each connection attempt, freeing up memory.

There is also a workaround for the memory issue: the TP4 stack can be allocated more memory by adjusting the [PLUTO] section of the PROTOCOL.INI file, as follows:

[PLUTO]

memory=8192