The sendmail program can run in two connection modes: as a daemon, accepting connections; or as a client, making connections. Each mode can connect to a port to do its work. The options for the client port are set by the ClientPortOptions option (ClientPortOptions). The options for the daemon are set by this DaemonPortOptions option.

This DaemonPortOptions option is used to customize the daemon’s SMTP service. The form for this option is as follows:

O DaemonPortOptions=pair,pair,pair               configuration file (V8.7 and later) 
-ODaemonPortOptions=pair,pair,pair               command line (V8.7 and later) 
define(`confDAEMON_OPTIONS',``pair,pair,pair'')  mc configuration (V8.7 and later) 
DAEMON_OPTIONS(``pair,pair,pair'')               mc configuration (V8.11 and later) 
OOpair,pair,pair                                 configuration file (deprecated) 
-oOpair,pair,pair command line (deprecated) 

The DaemonPortOptions option is set to a comma-separated list of pairs,[15] where each pair is of the form:


Nine keys are available. Prior to V8.7 they were case-sensitive and an unknown key was silently ignored. With V8.8 and later, an unknown key is still ignored but now causes the following error to be printed:

DaemonPortOptions unknown parameter "key"

Beginning with V8.10, you can declare multiple DaemonPortOptions options, where each causes the single listening daemon to accept connections over multiple sockets.

The list of all currently defined keys is shown in Table 24-14.

Table 24-14. DaemonPortOptions ...

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