cf/README for sendmail 8.12.3

Eric Allman of the Sendmail Consortium

Adding New Mailers Or Rulesets

   Sometimes you may need to add entirely new mailers or rulesets. They should be introduced with the constructs MAILER_DEFINITIONS and LOCAL_RULESETS respectively. For example:

MAILER_DEFINITIONS
Mmymailer, ...
...

LOCAL_RULESETS
Smyruleset
...

        Local additions for the rulesets srv_features, try_tls, tls_rcpt, tls_client, and tls_server can be made using LOCAL_SRV_FEATURES, LOCAL_TRY_TLS, LOCAL_TLS_RCPT, LOCAL_TLS_CLIENT, and LOCAL_TLS_SERVER, respectively. For example, to add a local ruleset that decides whether to try STARTTLS in a sendmail client, use:

LOCAL_TRY_TLS
R...

Note: you don't need to add a name for the ruleset, it is implicitly defined by using the appropriate macro.