Set up postfix (on Mac OS X 10.10 Yosemite) with Google Apps smtp

gistfile1.txt

$ sudo vim /etc/postfix/main.cf

Add the following to the 'relayhost' section:

  relayhost = [smtp.gmail.com]:587
  smtp_sasl_auth_enable = yes
  smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
  smtp_sasl_security_options = noanonymous
  smtp_use_tls = yes
  smtp_sasl_mechanism_filter = plain
  
$ sudo vi /etc/postfix/sasl_passwd

Add the following line:

  [smtp.gmail.com]:587 yourusername@domain.com:yourpassword
  
$ sudo chmod 600 /etc/postfix/sasl_passwd
$ sudo postmap /etc/postfix/sasl_passwd
$ sudo launchctl stop org.postfix.master
$ sudo launchctl start org.postfix.master

Then test with something like:

$ mail -s "This is a test" username@domain.com <<EOF
> This is just a test.
> EOF