Mozilla is already a very popular name in the software market, mostly thanks to the Firefox browser, so its own email client is bound to attract users as well. Thunderbird is a powerful application that borrows some features from Firefox, coming with add-ons and theme support, plus several other innovative features. Just like expected from an email client, Mozilla Thunderbird can be installed in a matter of seconds, but the hard part begins when creating an account. Novices are advised to use the wizard and complete each fields with the correct information, provided the email settings are known. As mentioned before, Mozilla Thunderbird can be heavily customized through plug-ins and themes, so having a look at Mozilla’s add-ons center is a must. It should be emphasized that, while Mozilla Thunderbird is friendly with computer resources, it might slow down if users install a large variety of add-ons and themes.