feedmail-sendmail-f-doesnt-sell-me-out

feedmail-sendmail-f-doesnt-sell-me-out is a variable defined in `feedmail.el'.
Its value is

nil

Documentation:
Says whether the sendmail program issues a warning header if called with "-f".
The sendmail program has a useful feature to let you set the envelope FROM
address via a command line option, "-f". Unfortunately, it also has a widely
disliked default behavior of selling you out if you do that by inserting
an unattractive warning in the headers. It looks something like this:

X-Authentication-Warning: u1.example.com: niceguy set sender to niceguy@example.com using -f

It is possible to configure sendmail to not do this, but such a reconfiguration
is not an option for many users. As this is the default behavior of most
sendmail installations, one can mostly only wish it were otherwise. If feedmail
believes the sendmail program will sell you out this way, it won't use the "-f"
option when calling sendmail. If it doesn't think sendmail will sell you out,
it will use the "-f" (since it is a handy feature). You control what
feedmail thinks with this variable. The default is nil, meaning that feedmail
will believe that sendmail will sell you out.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.1 of Emacs.