The "email" command:

Usage: fossil email SUBCOMMAND ARGS...

Subcommands:

   exec                    Compose and send pending email alerts.
                           Some installations may want to do this via
                           a cron-job to make sure alerts are sent
                           in a timely manner.
                           Options:

                              --digest     Send digests
                              --test       Resets to standard output

   inbound [FILE]          Receive an inbound email message.  This message
                           is analyzed to see if it is a bounce, and if
                           necessary, subscribers may be disabled.

   reset                   Hard reset of all email notification tables
                           in the repository.  This erases all subscription
                           information.  Use with extreme care.

   send TO [OPTIONS]       Send a single email message using whatever
                           email sending mechanism is currently configured.
                           Use this for testing the email configuration.
                           Options:

                             --body FILENAME
                             --smtp-trace
                             --stdout
                             --subject|-S SUBJECT

   settings [NAME VALUE]   With no arguments, list all email settings.
                           Or change the value of a single email setting.

   subscribers [PATTERN]   List all subscribers matching PATTERN.

   unsubscribe EMAIL       Remove a single subscriber with the given EMAIL.