XCON: Per-Domain-Bilateral-Info and Third Party Systems

MORE INFORMATION

This ability can be configured via the Windows NT Registry as follows:

1. Start Regedt32.exe.
2. Go to HKEY_LOCAL_MACHINE\SYSTEM\CURRENTCONTROLSET\SERVICES \MSExchangeMTA\Parameters
3. Add a value name (i.e. click on Edit-Add Value with the Parameters folder highlighted) called "Do not generate Bilateral Info" as type REG_DWORD and a hex value of 1. Important: This is case-sensitive and must be typed exactly as it is printed here:
   
   value 0x1 (0 is the default).

To avoid the loop detection, when a message enters new Microsoft Exchange Site, the MTA adds Per Domain Bilateral Information to the P1 Envelope to indicate the names of the Sites the message has passed through. During the loop detection, if the message reenters a Site, we check this mandatory Bilateral info to generate an NDR. Some 3rd party MTAs do not understand the mandatory Bilateral information, hence the registry key.

For additional information regarding the Per-domain-bilateral-information argument, please refer to the CCITT Blue Book, Rec. x.411, Clause 12.2.1.1.1.2.