Lightning Calendar Extension for Thunderbird Email

For years I have been relieving those annoying emails from scheduling systems asking to insert an appointment in my calendar.   I tried an integrated email/calendar package for Linux, but it did not do email very well (or anything else). So I was reduced to either ignoring the messages or trying to decode what they said. Recently I installed the Lightning calendar extension for Thunderbird email. This is small and works well. It decodes the incoming invitations,  lets you accept or reject, puts them in your calendar and sends a reply. It may do other things, but that was all I wanted. The extension is also available for Microsoft Windows and Apple Mac OS X.