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CloseReview for Google Calendar Tab by Emmanuel ROECKER
Rated 5 out of 5 stars
I created a new version (forked and updated original source code),
it works with last version of Thunderbird 60
It's named "Open Google Calendar"
https://addons.thunderbird.net/fr/thunderbird/addon/open-google-calendar/
Feel free to send any amount via Paypal :)
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