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CloseReview for Toggle Message Pane by 四天王寺
Rated 5 out of 5 stars
Thunderbird 115.6.1 で試してみましたが、確かに「便利」ですね。
トグルボタンの押下、一発で瞬時に「メッセージペイン」が目一杯拡張されます。
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