<snip> > The primary concern is with stopping mail with my domain as the sender and my > domain as the recipient if the sender IP is not within networks which I > control. <snip> > I'm not sure that this problem can be resolved within sendmail config files but > if anyone knows differently, please let me know. <snip>
Since this is a 'Basics' list, here are some places to get started. There isn't a solution to your specific question, but you can learn this stuff, and you might be able to work out an acceptable solution to your problem. In the sendmail source distribution cf/README cf/cf/knecht.mc doc/op/op.ps check_local package http://www.digitalanswers.org/check_local/ This is a whole set of add-ons you can install, or you can just read it to learn about rulesets. I'd like to repeat the caution that I think this is a complex problem and it will 'break' things. Remember that there are both ENVELOPE addresses and HEADER addresses in email. Remember that your relay will qualify unqualified HEADER sender addresses with the hostname of your relay.
