Under
certain circumstances, before sendmail delivers
to a file or through programs, it can assume the identity
(user-id and group-id) of
the controlling user (see Section 12.2.2 for a
description of this process). Beginning with V8.7, the
F=o delivery agent flag changes this behavior.
Specifying the F=o delivery agent flag causes
sendmail to assume the identity of the
recipient. Omitting the F=o delivery agent flag
causes sendmail to assume the identity of the
controlling user where appropriate. (See also the
F=S flag (F=S) as a way
to have sendmail assume specified
user-id and group-id
identities.)
In V5 and earlier configuration files (Section 17.5),
this delivery agent flag is automatically set for the
prog and *file* delivery
agents. Note that the U= delivery agent equate
(U=), when specified, always overrides the
controlling user.
