notification service added

postfix need to be installed

Remove the following two elements from
/System/Library/LaunchDaemons/org.postfix.master.plist:

<string>-e</string>
<string>60</string>
This will stop it exiting after 60 seconds.

Add the following element as a child of the <dict>...</dict> element in
the same plist file:

<key>KeepAlive</key>
<true/>
Reload the file:

cd /System/Library/LaunchDaemons
sudo launchctl unload org.postfix.master.plist
sudo launchctl load org.postfix.master.plist
postfix should now be running as a daemon.