Thunderbird is an open source email client from Mozilla, the creators of the highly popular internet browser Firefox.  Comparable to Microsoft Outlook, only it does not come standard with a calendar.

The beauty of Thunderbird is that like Firefox you are able to install add-on features and themes.  So if you need to have a calendar with your emails, simply go to the website, download and install through the application.

Features that come standard are:

• Advanced folder view.
• Message tagging with descriptors.
• Find bar for quick searches within displayed messages.
• Message history navigation.
• Phishing Protection.
• Pop and IMAP support.

As I’ve already mentioned, you can add additional features onto your application.  The “add-ons” range from contact management to additional privacy & security functions.  The add-on manager makes it easy to add or remove extensions to customize the look and tools to fit your needs.

The price for Thunderbird and all the additional add-on is FREE.