Persistent host status information

When HostStatusDirectory is enabled, information about the status of hosts is maintained on disk and can thus be shared between different implementations of sendmail. The status of the last connection with each remote host may be viewed with the command:

sendmail -bh

This information may be flushed with the command:

sendmail -bH

Flushing the information prevents new sendmail processes from loading it, but does not prevent existing processes from using the status information that they already have.