I use Postfix to relay system messages (e.g. a botched cronjob) over SSL to my Gmail account. These messages are otherwise “lost” because the email is being sent to a dormant mail transfer agent on my Mac. There’s way more that you can do with Postfix, but I’ll just cover the setup I did for my needs.
1. Create the Simple Authentication and Security Layer (SASL) password file.
sudo vi /etc/postfix/sasl_passwd
Enter and save the following
2. Create a Postfix lookup table for SASL.
sudo postmap /etc/postfix/sasl_passwd
3. Configure Postfix with
sudo vi /etc/postfix/main.cf
By default, everything is commented out. You can just append this to the end of file and save:
mydomain_fallback = localhost
mail_owner = _postfix
setgid_group = _postdrop
relayhost=smtp.gmail.com:587
# Enable SASL authentication in the Postfix SMTP client.
smtp_sasl_auth_enable=yes
smtp_sasl_password_maps=hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options=
# Enable Transport Layer Security (TLS), i.e. SSL.
smtp_use_tls=yes
smtp_tls_security_level=encrypt
tls_random_source=dev:/dev/urandom
5. Start postfix with
sudo postfix start
If you get an error, address the parameter in main.cf that is in the error and use
sudo postfix reload
to refesh Postfix. If everything looks good, then send an email
date | mail -s test your.name@gmail.com
If you don’t get an email fairly quickly, enter
mailq
and you should see the email there along with a description of any problems. If the mail is not in the queue, you most likely got something wrong in main.cf so you’ll need to do some debugging. If your mail queue starts to fill up during this process, you can clear it with
sudo postsuper -d ALL
6. Once you have everything working, you can set Postfix to start on boot by adding a key to /System/Library/ LaunchDaemons/org.postfix.master.plist. If you have Property List Editor (or something similar), you can add the key RunAtLoad of type Boolean with a value that is checked.
Alternatively,
sudo vi /System/Library/LaunchDaemons/org.postfix.master.plist
and add the following just before the tag </dict>
<true/>
You can control whether your job is to be kept continuously running by using KeepAlive .
