# Restart sendmail (probably "/etc/init.d/sendmail restart"). 

 # Try sending a test message from a local address through the secondary to something@mydomain.com. 

  

 You should be all set. Try making the primary unreachable from the secondary, just to be sure, and repeat step 6. The easiest way to make it unreachable is 'preferredmx# route add secondarymx.otherdomain.org dev lo'. Do __not__ do that if you are presently logged into preferedmx from secondarymx, and that is the only way you can reach preferredmx. By doing this you are (temporarily) adding a bad route between the two boxes.. if you don't understand the implications of that, you probably don't want to do it. Be sure to 'route del secondarymx.otherdomain.org dev lo' after you are done testing.. 

  

 !!!make in /etc/mail doesn't build sendmail.cf 

  

 So you just updated your /etc/mail/sendmail.mc, but when you run 'make', nothing happens. 

  

 If you run redhat, this means you need to install the sendmail-cf package. 

  

 Why there is a seperate package for people who want to actually *configure* sendmail, I don't know.