<MAILSERVER_MANAGER>
  dsn dbi:mysql:mailserver
  user some_username
  password some_password
</MAILSERVER_MANAGER>
<MAILSERVER_RUNTIME>
  dsn dbi:mysql:mailserver
  user some_username
  password some_password
</MAILSERVER_RUNTIME>
<MAILSERVER_TESTING>
  dsn dbi:sqlite::memory:
</MAILSERVER_TESTING>