How to restore the Terminal mail program to default settings So a number of months ago I was messing around in Terminal trying to get my Mac to send an email from the command line. Unfortunately, I don't remember everything I did but I know I was messing around with postfix and creating a sasl password file, etc. I never got it to work and gave up.

Now I want to try again but don't remember what I already did. Is there a way to restore postfix or the mail terminal programs to their default settings so I can get a fresh start?
There must be two files main.cf.default and master.cf.default which you can use to overwrite the messed up ones, thus resetting them to the distribution default values.

cp /etc/postfix/main.cf.default /etc/postfix/main.cf
cp /etc/postfix/master.cf.default /etc/postfix/master.cf


If you can't find the default ones, you may try to copy them from another computer.

Also, you may type postconf -d which will print main.cf default parameter settings instead of actual settings.  Specify -df to fold long lines for human readability (Postfix 2.9 and later). Read more here.