Thunderbird 52.0

此軟體可以讓新手輕鬆上手，快速設定郵件帳號，使用者只要輸入使用者名稱、E-mail、個人密碼，即可新增。使用者可享受全新的體驗，包括分頁、搜索郵件和備存功能，增加使用者的方便。

• Thunderbird繼承了Mozilla瀏覽器的分頁功能，讓使用者可以加速瀏覽，同時間觀看多封郵件，對於時常要回覆多封郵件的商務人士來說十分方便。
• 遷移助理可以幫助使用者快速建立新帳號、密碼、個人資料。
• 輕鬆加入新朋友，只要透過按下寄件者右方的星星即可增加新的聯絡人，雙重點擊即可新增照片、生日或是其他資訊。
• 透過附件提醒功能，系統會自動搜尋郵件內是否有attached、attachment或是其他表示附檔的字眼，提醒使用者是否已經上傳附檔。
• 活動管理員會將Thunderbird和根據使用者不同的登入帳號來做分類，將彼此之間互動記錄下來，方便使用者查閱。
• 搜索功能強大，此軟體擁有時間軸和篩選器工具，不管郵件日期已多久遠，使用者得以透過此功能馬上找出郵件。
• 提供個人化設定，附加元件管理員中內含各式各樣的選擇供使用者選擇，數百種的套件，包括個性面板、行程管理等等，讓原本平淡的郵件介面變成更有趣。
• 提供安全和隱私權的保證，使用者將垃圾信件標示後，系統會學習和過濾特定郵件。此外系統會偵測信件中特定字眼，提醒使用者也許是網路詐騙。
• 系統會自動升級，主動提醒使用者該更新版本，以確保使用者的隱私安全。

New:
Folder pane toolbar and folder view selector (replacement for folder view arrows).
Optionally remove corresponding data files when removing an account from Thunderbird.
Import settings from Becky! Internet Mail.
Possibility to copy message filter.
Dictionary setting is restored when editing a draft. Content-Language header (RFC 3282) transmitted with message.
Calendar: Event can now be created and edited in a tab.
Calendar: Processing of received invitation counter proposals.
Chat: Support Twitter Direct Messages.
Chat: Liking and favoriting in Twitter.
Chat: XMPP: Support SASL SCRAM authentication mechanism.
Chat: Support Jabber/XMPP Message Carbons (XEP-280).
Changed:
IMPORTANT: The way images are included in a compose window has changed. Images are now included as data URIs and not as references to parts of other messages or operating system files. This allows better interoperability with office packages such as MS Office or LibreOffice. Images linked from locations on the internet will no longer be downloaded and attached to the message automatically. This can be changed for each image individually via the Image Properties dialog or globally by setting the preference.
mail.compose.attach_http_images.
Correspondents column now default for all new folders, can be switched off with preference mail.threadpane.use_correspondents.
When replying to a mailing list, reply will be sent to address in From header ignoring Reply-to header.
On Linux PulseAudio is now required to play sound.
Formatting toolbar is now left in place when delivery format is switched to plain text only.
Messages in IMAP folders read on external device are now filtered by default.
Folders backed by mbox storage larger than 4GB are supported without warning (unless preference mailnews.allowMboxOver4GB is set to false).
IMAP caching now uses Mozilla's latest caching technology.
Chat: Removed Yahoo! Messenger support (since Yahoo removed support).
Fixed:
Message preview pane non-functional after IMAP folder was renamed or moved.
Editing in paragraph format: Pressing Shift+Enter sometimes doesn't move the cursor to the next line.
Various corrections when composing messages in paragraph format.
Paste as quotation doesn't always work.
Long lines in plain text replies not properly wrapped.
Undesired white-space before signature in paragraph mode.
When attachment unavailable, compose shows endless "Attaching..." message instead of error.
Text encoding of reply sometimes incorrect (uses encoding of last viewed message).
Text encoding of message display, reply or forwarded message sometimes incorrect (uses encoding of attachment).
Delivery Format not preserved for saved drafts (Auto-Detect|Plaintext|HTML|Both).
Reply to own e-mail does not reply with the correct identity.
IMAP message part caching.
Links with escaped non-ASCII (international) characters can't be clicked.
Calendar: Events specified in timezone "local time" generate alerts in UTC time.
Chat: XMPP Resource collisions.