Aug 23, 2018 - Microsoft has warned Mac subscribers of Office 365 that they must be running. At that time, the Office applications — Word, Outlook, Excel.
TT DeepDark
Simple and smooth dark complete theme for Thunderbird
by steva
MS Office 2003 JB Edition
MS Office 2003 Theme.
by Jarek Bialkowski
Nuvola TB
Theme based on the Nuvola icon set by David Vignoni (http://icon-king.com/?p=15). You can find developer versions under http://mozilla.paenglab.ch/
by Paenglab
Phoenity Shredder
A simple and colorful theme for everyone.
by Dillinger
Walnut2 for Thunderbird
Walnut2 for Thunderbird, based on icons from art.gnome.org. Walnut2 is based on Walnut but with better looking wood panels. Supports Thunderbird versions 53.0 to 60.0. From version 61.0, Thunderbird will drop support for full custom themes.
by alfredkayser
Metal Lion Sea Monkey
Metal Lion meets SeaMonkey.
by Frank Lion
Monterail
Monterail TB theme with official icons from Monterail
by Paenglab
Monterail Full Dark
Monterail Full Dark, a Thunderbird theme inspired by the mockup of Monterail
by conema
Walnut for Thunderbird
Walnut for Thunderbird, based on icons from art.gnome.org, and sporting a wooden look. Supports Thunderbird versions 53.0 to 60.0. From version 61.0, Thunderbird will drop support for full custom themes.
by alfredkayser
Classic TB2
Theme using mostly TB2 icons plus the best of TB1.5, TB3, and later versions.
by Corey Drechsler
Monterail Dark
Monterail Dark, a Thunderbird theme inspired by the mockup of Monterail
by conema
Nautipolis for Thunderbird
Nautipolis for Thunderbird: High-quality, solid theme based on icons from art.gnome.org. Supports Thunderbird versions 53.0 to 60.0. From version 61.0, Thunderbird will drop support for full custom themes.
by alfredkayser
Metal Lion Silver Sea Monkey
Metal Lion meets SeaMonkey and makes it shine....
by Frank Lion
Silvermel
A Creamy Silvery Experience
by ShareBird
Tangobird
Theme with Tango icons for Thunderbird.
by Haven667
Noia 2.0 eXtreme (v3.x)
This Noia 2 eXtreme theme v3.x version has been rewritten / v2.x (still available but only for old TB). Options are available with an associated extension. See also my Web site for last versions (compatible TB 60). Icons by Carlitus.