Quicktext is an extension for Thunderbird that lets you create templates that can be easily inserted into your own emails.

Use it to add signatures for your emails (you need to use url and an online source for images). Quicktext is the perfect tool to help you quickly answer routine, repetitive emails. Quicktext performs both simple and complex tasks. The program can insert different signatures into your emails depending on whom you are sending the email to. Quicktext now exists as two versions: Quicktext and Quicktext Pro. The Pro version have even more features and can be found on the extensions homepage. Even better, you can use variables like [[TO=firstname]] to personalize your emails. You can also specify an emails subject and which attachments to add when creating a template for your email. There are many easy ways to insert a template: by toolbar; by adding a button to the main-toolbar; you can right-click and choose a template; you can set up shortcuts like Alt+1 to insert a specific template; and most useful of all, the keyword feature. Just add a keyword to a template and then write that word in the email and press TAB---the keyword is then replaced by the template.