The only available option to customize the archive is the advanced config editor which makes it possible to change the archiving granularity, names and other settings. The Thunderbird 3 add-on Message Archive Options is basically a frontend for the advanced config options.

There are two options that the add-on offers. The first allows the Thunderbird user to customize the granularity of the archiving function in Thunderbird. It is first and foremost possible to switch from the one folder per year structure to either to a single folder structure or one with months as the additional levels. The date format for the year and year – month structure can be altered as well.

The second option is to add a key modifier to the archiving shortcut. It is possible to add Alt, Shift or Control to [a] to archive the selected email messages.

Message Archive Options does not invent the wheel anew but it offers easier access to customizing the email archive in Thunderbird 3. The add-on is only compatible with Thunderbird 3 and available at the Mozilla website.