sendmail -U

[Marius Gedminas]

Browsing through sendmail(8) man page I stumbled upon this option:

     -U          Initial (user) submission.  This should always be set when
                 called from a user agent such as Mail or exmh and never be
                 set when called by a network delivery agent such as rmail.

What does it do and why isn't it used in the default $sendmail value?
Just curious.

Marius Gedminas
-- 
If two wrongs don't make a right, try three wrongs.