PC Adm: Connecting Two Postoffices by Using Null Modem

• Microsoft Mail for PC Networks, versions 2.1e, 3.0, 3.0b, 3.2, and 3.2a

By making changes to the Microsoft Mail for PC Networks script files, you can configure more than one COM port for an external computer to allow communications to another external computer. This will free one COM port for modem communications to another postoffice, while a null modem cable can be used to connect the two external computers to establish postoffice- to-postoffice communications.

The following steps allow two computers, each running the External Mail program, to communicate by using a serial null modem connection on COM1, and allow the COM2 port of one of the computers running the External Mail program to communicate to a remote client or another External Mail program using modem communications.

1. Modify the NULLMDM.MDM file and add the text "PORT COM1" (without the quotation marks) to the Initialize, Call, and Answer segments of the script file. Compile the script using the SCRCOMP.EXE utility to create a NULLMDM.SCR compiled script file (for more information, see Appendix N of the Microsoft Mail for PC Networks "Administrator's Guide").

2. Start the Mail Administrator (ADMIN.EXE) program, select External-Admin, Setup, and type "<NULLMDM" in the Phone Number field. This will inform the ADMIN.EXE program that any mail to transfer to the first postoffice (PO1) will travel through the NULLMDM script, which you set to use the COM1 port (in step 1).

3. Choose Config, Serial, and choose COM2 in the Comm. Port field. This informs ADMIN.EXE that communications with the Remote clients will take place through the COM2 port.

4. The External Mail program connected to the second postoffice (PO2) must use the script file that matches the modem type connected to the External Mail program. For example, if the modem type connected to the External Mail program going to PO2 is Hayes V-Series, the EXTERNAL command-line should read as follows:

         external -dmn -tvseries -hm