I had been using Mozilla Thunderbird as my preferred desktop email client for more than half a decade already (we’re still relying on Microsoft Outlook for our corporate emails at the office, though).
Thunderbird will just be a plain but powerful email app without Lightning – the extension that integrates the Sunbird calendar to Thunderbird. Often times, I am being asked if they can use their Google Mail (Gmail) accounts in Mozilla Thunderbird – of course, yes! I am even checking my corporate emails at home using Thunderbird (in IMAP mode).
And since Gmail comes with a built-in (Google) Calendar, why not maximize the use of Mozilla Thunderbird and have it synched to Lightning. Here’s how to do it:
Make sure that the latest version of Lightning is installed as an Add-on in your Mozilla Thunderbird
Create a new Calendar from the File menu
In Create New Calendar > Locate your calendar option, choose “On the Network” then click on “Next”
Choose CalDAV as the new calendar format
Click on “Next” then give your calendar its Name then click again on “Next” and you’re done!
You may now update and check your calendar from within the web interface (in Gmail) or from within the Calendar tab in Mozilla Thunderbird, just make sure to hit the Synchronize button every once in a while.