Thunderbird 24.4.2 has been released and can be updated using PPA.

Thunderbird is a free open-source mail client and the most popular mail client in Linux. It has been updated with the Thunderbird version 24.4.2. You can view detailed release logs for security updates.

Thunderbird 24.4.2 installation command (Ubuntu 12.04, 12.10, 13.10, 14.04, Linux Mint 16, Linux Mint 14, Linux Mint 13, Elementary OS 0.2)

Open the terminal and enter the following command:

Echo-e "ndeb http://downloads.sourceforge.net/project/ubuntuzilla/mozilla/apt all main" | sudo tee-a/etc/apt/sources. list>/dev/null
Sudo apt-key adv -- recv-keys -- keyserver keyserver.ubuntu.com C1289A29
Sudo apt-get update
Sudo apt-get install thunderbird-mozilla-build

If you have installed Thunderbird 24.4.0 before, run the following command to update it:

Sudo apt-get update
Sudo apt-get install thunderbird