How can I manage services running in a FreeBSD jail?

I’ve inherited some systems that runs on the FreeBSD operating system and inside jails. Basically the services running are old versions of qmail, spamd, Dovecot, etc. None of the versions are up to date or even maintainable any more. At present we can’t move from these systems but I would at least like to be able to troubleshoot them. My question: Normally I would be able to run for example service qmail status and get some info about the top level process. How do I do this inside a jail? In the case of the qmail process I can use qmailctl but what would be the equivalent for spamd or Dovecot? Also how do you go about troubleshooting these types of services? The logs don’t really give a very good steer on what could be going wrong.