This is true, but "localhost.localdomain" won't work.
The only thing I did in sendmail.cf, after finding it in one of those user forums, is change
O DaemonPortOptions=Port=smtp,Addr=127.0.0.1, Name=MTA
to
O DaemonPortOptions=Port=smtp, Name=MTA
and restart sendmail
The first way was rejecting all mail. They even gave us some smtp address (smtp.company.net)
but that got rejected too.
================
the mail command just calls sendmail, it has no means of setting from.
I think mutt can be coerced, but I've never tried.
If sendmail's idea of the host name is the same as you can see from the
Internet, then there shouldn't be a problem: Ffor examile
fff.example.com resolves to your client's IP address
sendmail (or other MTA) thinks it's called fff.example.com
then all will be well.
In practice, it doesn't matter what the name is so long as it resolves,
but it would be a bit rude to pinch IBM's.
In sendmail (and probably other MTA) you can also use address rewriting
(masquerading). See DM in sendmail.cf
-The only thing I did in sendmail.cf, after finding it in one of those user forums, is change
O DaemonPortOptions=Port=smtp,Addr=127.0.0.1, Name=MTA
to
O DaemonPortOptions=Port=smtp, Name=MTA
and restart sendmail
The first way was rejecting all mail. They even gave us some smtp address (smtp.company.net)
but that got rejected too.
================
the mail command just calls sendmail, it has no means of setting from.
I think mutt can be coerced, but I've never tried.
If sendmail's idea of the host name is the same as you can see from the
Internet, then there shouldn't be a problem: Ffor examile
fff.example.com resolves to your client's IP address
sendmail (or other MTA) thinks it's called fff.example.com
then all will be well.
In practice, it doesn't matter what the name is so long as it resolves,
but it would be a bit rude to pinch IBM's.
In sendmail (and probably other MTA) you can also use address rewriting
(masquerading). See DM in sendmail.cf
