[2] [CITE@ja[Thunderbird — メールをもっと簡単に。 — Mozilla]] ([TIME[2018-04-04 19:13:07 +09:00]]) <https://www.mozilla.org/ja/thunderbird/>

[1] [CITE@en-US[Thunderbird’s Future Home | The Mozilla Thunderbird Blog]]
([TIME[2017-05-14 13:00:14 +09:00]])
<https://blog.mozilla.org/thunderbird/2017/05/thunderbirds-future-home/>

[3] [CITE@ja[Mozilla Thunderbird - Wikipedia]]
([TIME[2018-04-03 00:43:40 +09:00]])
<https://ja.wikipedia.org/wiki/Mozilla_Thunderbird>