The channel programs test_smtp_master and test_smtp_slave are provided as models upon which additional channels using the SMTP protocol can be built. They are intended as examples only and not as production channel programs.

Both programs require that the logical name PMDF_CHANNEL (on OpenVMS) or the environment variable PMDF_CHANNEL (on UNIX and NT) translate to the name of the channel they are servicing.

When test_smtp_master is executed, it looks in the queue cache database for messages waiting to be processed by the channel PMDF_CHANNEL. On OpenVMS, SMTP commands are written to SYS$OUTPUT and responses are expected on SYS$INPUT; on UNIX and NT, SMTP commands are written to stdout and responses are expected on stdin.

Similarly, on OpenVMS, test_smtp_slave accepts SMTP commands on SYS$INPUT and writes responses to SYS$OUTPUT; on UNIX and NT, test_smtp_slave accepts SMTP commands on stdin and writes responses to stdout.

The distributed master.com command procedure on OpenVMS and the pmdf run utility and Job Controller on UNIX never invoke test_smtp_master and will have to be modified in order to use test_smtp_master. The code supporting tcp_master can be used as a model to drive test_smtp_master.

test_smtp_master includes code to distinguish between use as a direct connection to the target system and use for routing through a gateway. This facility parallels the gateway support found in TCP/IP channels, namely support for the daemon keyword.