Depends on what you are looking for as to what answer is given. What is your definition of a template? I see the native templates as basically useless except as a source of boiler plate text. The mail merge addon offers the features of merging data from address books or CSV files into individual emails a very handy tool in it's own right. https://addons.thunderbird.net/en-US/thunderbird/addon/mail-merge/ Then there is the smart templates https://addons.thunderbird.net/en-US/thunderbird/addon/smarttemplate4/ This is probably what you are looking for.