TCP/IP channels are used to link PMDF to TCP/IP based networks such as
the Internet. The TCP/IP channels all use the Simple Mail Transfer
Protocol (SMTP), including extensions such as those described in RFCs
1426, 1869, 1870, and 1891.1 The description of this
protocol and extensions to it can be found in files such as
rfc2822.txt in the
rfc subdirectory of the
PMDF documentation directory.
On UNIX and NT, PMDF's multithreaded TCP SMTP channel uses the TCP/IP network protocol stack supplied with the operating system.
On OpenVMS, PMDF supports the following TCP/IP packages:
The multithreaded TCP SMTP channel includes a multithreaded SMTP server
which runs under the control of the PMDF Service Dispatcher. Outgoing
SMTP mail is processed by the multithreaded PMDF channel program
tcp_smtp_client), run as needed under the control of
master.com (OpenVMS) or the PMDF Job Controller (UNIX and
Configuration instructions are presented in this chapter for the multithreaded TCP/IP channel.
Section 23.3, towards the end of this chapter describes how to establish a "gateway" channel to route mail through another system, as for instance to a mailhub or firewall system. Section 23.4, at the end of this chapter, describes performing "polling" with TCP/IP channels, that is, requesting that a remote system attempt to deliver any stored messages to your system; for instance, this can be particularly useful over "intermittent" sorts of TCP/IP links, such as dial-up connections.
1 Two additional SMTP channels, SMTP over task-to-task DECnet and "generic" SMTP channels, are presented in Chapter 22 and Chapter 28.
2 The multithreaded TCP SMTP channel replaces PMDF single-threaded TCP/IP channels specific to the above TCP/IP packages. For sites upgrading from older versions of PMDF, see the OpenVMS Edition of the PMDF Installation Guide for instructions on switching to using the multithreaded TCP SMTP channel.
3 PMDF has been tested against TCPware versions through 5.5.