Les Mikesell wrote:
John Summerfield wrote:
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
You probably don't want to touch sendmail.cf (or even try to read
it...). Instead, be sure you have the sendmail-cf package installed,
edit /etc/mail/sendmail.mc, and change
dnl MASQUERADE_AS(`mydomain.com')dnl
removing the leading dnl and replacing mydomain.com with something that
is internet-legal. If your software runs as root when it sends mail,
you'll also need to add a leading dnl to the line:
EXPOSED_USER(`root')dnl
to comment it out. Then restart sendmail.
I can never remember that new-fangled way; what I said is what I used to
do on OS/2. These days, I use postfix which is much more straightforward.
Thanks Les for setting the record a little straighter.