Generic SMTP channels

The channel programs  and    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 environment variable PMDF_CHANNEL (on UNIX) translate to  the name of the channel they are servicing -- and expect that channel  to be defined in the MTA configuration.

When  is executed, it   asks the Job Controller  for messages waiting to be processed by the channel  PMDF_CHANNEL. SMTP commands are written to  and responses are expected on.

Similarly,  accepts SMTP commands on    and writes responses to.

The  the   utility and  the regular configuration of the  Job Controller never  invoke   and will have to be modified in  order to use. The configuration to execute  can be used as a model to drive.

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   option.

Though  and   never open or receive, respectively,  an actual TCP/IP connection,  if the environment variables TRANSPORTINFO and APPLICATIONINFO are set,  then these programs will use that information to initialize the relevant fields that would be  present in a real SMTP-over-TCP/IP message transport.

and  perform normal MTA channel initialization steps, including  consulting the MTA configuration to determine if the named channel (the channel PMDF_CHANNEL translates to) has any   set; they check for any  TCP/IP-channel-specific options; and they "support" typical channel options relevant to SMTP-over-TCP/IP channels, such as  ,  ,  , and (as previously mentioned) the   channel option.

See also:
 * Job Controller
 * daemon Option
 * local_host_alias Option
 * master_debug Option
 * slave_debug Option
 * smtp Option
 * TCPIP channels
 * TCPIP-channel-specific options
 * Other channels