Mail addressed to a local user
that includes the name of the local host as part of the address
(i.e., firstname.lastname@example.org) is delivered locally.
From V8.1 to V8.6 sendmail, if the address has a
host part, lookups in the User Database (userdb) and the additional processing of the
localaddr rule set 5 (Section 19.6) are skipped. Under V8.6, addresses with just
the user part are always processed by the User
Database and the localaddr rule set 5.
The V8.6 notsticky feature changes this logic. If
this feature is chosen, all users are looked up in the User Database,
and the additional processing done by the
localaddr rule set 5 is skipped.
Beginning with V8.7, the default is as if
notsticky were used, and thus the
stickyhost feature can be used to restore the