+ mailbox-count produces a simple count of mailboxes that exist
+ per-domain in some SQL database. The default queries are compatible
+ with the [PostfixAdmin](https://postfixadmin.sourceforge.net/)
+ schema, but it is possible to supply your own queries.
+
+ The summary report lists each domain, along with the number of
+ mailboxes owned by that domain. The order is determined by the
+ summary query, which lists the domains alphabetically by
+ default. The default detail report shows the same, but also contains
+ a list of each individual mailbox (again in alphabetical order)
+ belonging to the domains.
+
+ A full set of options and examples can be found in the man page.
+