The -bH command-line switch causes sendmail to clear (purge) all the persistent host-status information that was being saved as a result of the HostStatusDirectory option (HostStatusDirectory). Note that the HostStatusDirectory directory is not itself removed, but all the subdirectories under it are. The purgestat(1) (Section 15.1.4) command-line command is a synonym for this switch.

Note that, beginning with V8.10, sendmail only purges host-status files that exceed the timeout set by the Timeout.hoststatus option (See this section).