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Provider for Google Calendar

Allows bidirectional access to Google Calendar

Rated 3 out of 5 stars (1,650)
195,047 users

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British English Dictionary (Marco Pinto)

A fork of Mark Tyndall's add-on, based on David Bartlett's
British Dictionary R1.19 for Firefox, Thunderbird and SeaMonkey.

V3.3.3 has 140 000+ new words and also fixes.

Rated 5 out of 5 stars (83)
172,300 users

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English United States Dictionary

English United States (en-US) Dictionary as shipped with Thunderbird 115 ESR and Firefox 115 ESR.

Rated 4 out of 5 stars (39)
71,955 users

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Deutsches Wörterbuch

Deutsches Wörterbuch (neue Rechtschreibung) für die Rechtschreibprüfung in Mozilla-Produkten

Rated 4 out of 5 stars (82)
238,548 users

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Diccionario de Español/España

Diccionario de Español/España

Rated 4 out of 5 stars (167)
63,965 users

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Mail Merge

Create and Save or Send Multiple Individual and Personalized Messages from a Draft

Rated 5 out of 5 stars (226)
68,579 users

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DKIM Verifier Featured

Verifies the DKIM-Signature of an e-mail.

Rated 4 out of 5 stars (45)
18,379 users

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Dizionario italiano

Add support for Italian to spellchecking

Rated 4 out of 5 stars (71)
78,019 users

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Send Later

True "Send Later" functionality to schedule the time for sending an email.

Rated 5 out of 5 stars (263)
104,772 users

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Woordenboek Nederlands

Woordenboek Nederlands met de woordenlijst van OpenTaal.

Rated 3 out of 5 stars (70)
23,493 users

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Signature Switch

Switch the signature on/off or choose a new one from your predefined set.

Rated 4 out of 5 stars (272)
52,661 users

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Diccionario español Argentina

Diccionario ortográfico de español de Argentina.

Rated 4 out of 5 stars (93)
13,489 users

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QuickFolders (Tabbed Folders)

The "Swiss army knife" of folders. Turn your favorites into tabs - open folders and subfolders, move mails without scrolling around or searching. powerful + easy.

See new mail at a glance after automatic filtering - supports quickFilters addon!

Rated 5 out of 5 stars (187)
15,289 users

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Український словник

Український словник перевірки орфографії

Rated 5 out of 5 stars (57)
11,471 users

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Diccionari català (general)

Diccionari ortogràfic lliure català (versió general).

Rated 4 out of 5 stars (40)
13,359 users

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Canadian English Dictionary

For some reason, Mozilla doesn't have a Canadian localization team, but I know that even the British dictionary doesn't quite cut it for the truly patriotic.

Rated 4 out of 5 stars (82)
9,496 users

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Emoji

Add emojis to your e-mails.

Rated 4 out of 5 stars (64)
25,107 users

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Addressbooks Synchronizer

Synchronizes selected addressbooks with other instances of thunderbird
using local files, webdav servers or imap servers

Rated 4 out of 5 stars (79)
25,803 users

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Deutsches Wörterbuch (de-DE), alte Rechtschreibung

Wörterbuch deutsch (alte Rechtschreibung) für die Rechtschreibprüfung in Firefox und Thunderbird + alte Rechtschreibung + bisherige Rechtschreibung + klassische Rechtschreibung + bewährte Rechtschreibung + unreformierte Qualitätsrechtschreibung +

Rated 5 out of 5 stars (20)
9,545 users

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quickFilters

Quickly generate mail filters on the fly, by dragging and dropping mails and analyzing their attributes. Create a filter in less than 10 seconds, it's as easy as: drag, click, click.

By popular demand, supports SORTING filters alphabetically.

Rated 5 out of 5 stars (70)
13,682 users

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