How to start Thunderbird minimized on start-up?

I used this addon to start thunderbird in minimized mode by default and added a startup entry for thunderbird by following this guide.

Let me make it clear, at least for people like me.

Making sure that thunderbird is automatically started on logon, involves just three steps:

1. Install "FireTray" addon on thunderbird
2. check "start application hidden to tray" option in FireTray preferences (Thunderbird -> Tools -> addons -> firetray -> preferences -> under tab "windows")
3. Follow this answer (its quick) to add thunderbird to startup (Note: the command field therein should be: thunderbird or /usr/bin/thunderbird)

Note that FireTray addon is a must have. Most people don't actually mean to quit entirely like the default behavior is, when they say "close" to window. They sure expect thunderbird to run in background and notify of all new email arrivals. And FireTray deals exactly with this problem.

http://ubuntuforums.org/showthread.php?t=1529056