The stock RH6 sendmail.cf does not contain any mailertable
rules, which is rather confusing for people since in
/etc/mail a sample mailertable is provided. Given that it's
only 50 extra lines in the sendmail.cf, it should be
provided by default.
Entries for the domaintable and virtusertable are present,
it's only the mailertable which is lacking.
FEATURE(mailertable) added in sendmail-8.9.3-15.