We stop short of rewriting all playbooks for Prometheus, and instead
add references to the task of adding playbooks for
everything (prometheus-alerts#16) where we found references to
nagios.

service/email.md

@@ -998,13 +998,13 @@ release in over 4 years (as of late 2022).
 
 ## Monitoring and metrics
 
-The Postfix server is monitored by Nagios, as with all servers in the
+The Postfix server is monitored by Prometheus, as with all servers in the
 `publicmail` group. This only checks that the SMTP port is open. We do
 not have end to end delivery monitoring just yet, that is part of the
 [improve mail services milestone](https://gitlab.torproject.org/groups/tpo/tpa/-/milestones/4), specifically [issue 40494](https://gitlab.torproject.org/tpo/tpa/team/-/issues/40494).
 
 The submission server is monitored like other mail servers that have
-`mail_processing` enabled, which is that it has the `mtail` exporter
+`profile::postfix::mtail_monitor` enabled, which is that it has the `mtail` exporter
 (`profile::prometheus::postfix_mtail_exporter`). The [Grafana
 dashboard](https://grafana.torproject.org/d/Ds5BxBYGk/postfix-mtail?orgId=1&var-node=submit-01.torproject.org) should provide shiny graphs.