The "alerts" command:

Usage: fossil alerts SUBCOMMAND ARGS...

Subcommands:

   pending                 Show all pending alerts.  Useful for debugging.

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

   send                    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       Write to standard output

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

   status                  Report on the status of the email alert
                           subsystem

   subscribers [PATTERN]   List all subscribers matching PATTERN.

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

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

   unsubscribe EMAIL       Remove a single subscriber with the given EMAIL.