EDIT: seems like you are talking about mail aliases.
/etc/mail/aliases. After editing that file, run
I do not believe that
Sendmail has transport map capabilities, at least not that i know of.
The feature you are looking for is available in
Postfix out of the box. Not sure how much this answer would help you though...
There used to be a package called
redhat-switchmail that kind of accomplished that, but I am not sure if it is still available, or if its even compatible with your system.
/etc/mail/local-host-names is just for that... local host names... the domains your sendmail server accepts mail for.
What exactly you want to accomplish with
/etc/hosts I am not sure...
Depending on your configuration and version of your
Sendmail, you need to edit
/etc/mail/sendmail.mc and then "make it" into
/etc/mail/sendmail.cf. On older versions, you edit
/etc/mail/sendmail.cf, but i do not suggest you touch either one of those files if you do not know what you are doing. They are pretty cryptic, to say the least.