Hi everyone!

is there a way to force sendmail to authenticate the users if the
email sender field is "From user@mydomain.com"?
this because i receive a lot of emails where the sender smtp field is
forged by spammers, this enables them to send emails to my domain without being authenticated.

I would also like to force authentication to "group" emails account
(like staff@mydomain.com) only to authenticated users? this would
limit the spam from users@other_domain.com to staff@mydomain.com.

maybe i could implement those features with spamassassin although sendmail maybe seems more right, what do you think?

my version: Sendmail 8.13.1/8.13.1

thankyou very much !
damien