Below are hotkeys for Mozilla Thunderbird email client.
Application
New message Ctrl + N
Ctrl + M
Reply to Message (sender only) Ctrl + R
Reply to All in Message (sender and all recipients) Ctrl + Shift + R
Reply to List Ctrl + Shift + L
Forward Message Ctrl + L
Edit Message as New Ctrl + E
Starting a new message in non-default format (Plain text vs. HTML) Hold Shift while clicking any one of these buttons:
Write, Reply, Reply All, Reply List, or Forward;
or Right-click existing message, then hold Shift while choosing any one of the following from the context menu:
Reply to Sender Only, Reply to All, Reply to List, or Forward.
Get New Messages for Current Account F5
Get New Messages for All Accounts Shift + F5
Open message (in new window or tab) Ctrl + O
Enter
Open message or folder in a new tab in the background Middle-click the message or folder, or
Right-click the message or folder, then choose Open Message in New Tab or Open in New Tab from the context menu
Open message or folder in a new tab in the foreground Shift + Middle-click the message or folder, or
Right-click the message or folder, then hold Shift while choosing Open Message in New Tab or Open in New Tab from the context menu
Open message in conversation Ctrl + Shift + O
Zoom In Ctrl + +
Ctrl + =
Ctrl + scroll wheel up
Zoom Out Ctrl + -
Ctrl + scroll wheel down
Reset Zoom Ctrl + 0 (zero)
Expand Collapsed Thread →
Collapse Expanded Thread ←
Expand All Threads *
Collapse All Threads
Newsgroups: Ignore or Unignore Thread K
Newsgroups: Ignore or Unignore Subthread Shift + K
Newsgroups: Watch Thread W
New message Ctrl + N
Ctrl + M
Reply to Message (sender only) Ctrl + R
Reply to All in Message (sender and all recipients) Ctrl + Shift + R
Reply to List Ctrl + Shift + L
Forward Message Ctrl + L
Edit Message as New Ctrl + E
Starting a new message in non-default format (Plain text vs. HTML) Hold Shift while clicking any one of these buttons:
Write, Reply, Reply All, Reply List, or Forward;
or Right-click existing message, then hold Shift while choosing any one of the following from the context menu:
Reply to Sender Only, Reply to All, Reply to List, or Forward.
For keyboard shortcuts during message composition, see Writing Messages.
Receiving and reading messages
Get New Messages for Current Account F5
Get New Messages for All Accounts Shift + F5
Open message (in new window or tab) Ctrl + O
Enter
Open message or folder in a new tab in the background Middle-click the message or folder, or
Right-click the message or folder, then choose Open Message in New Tab or Open in New Tab from the context menu
Open message or folder in a new tab in the foreground Shift + Middle-click the message or folder, or
Right-click the message or folder, then hold Shift while choosing Open Message in New Tab or Open in New Tab from the context menu
Open message in conversation Ctrl + Shift + O
Zoom In Ctrl + +
Ctrl + =
Ctrl + scroll wheel up
Zoom Out Ctrl + -
Ctrl + scroll wheel down
Reset Zoom Ctrl + 0 (zero)
Expand Collapsed Thread →
Collapse Expanded Thread ←
Expand All Threads *
Collapse All Threads
Newsgroups: Ignore or Unignore Thread K
Newsgroups: Ignore or Unignore Subthread Shift + K
Newsgroups: Watch Thread W
For keyboard shortcuts to move between your messages, see Moving around Thunderbird.
Managing your messages
Print message or selected message text Ctrl + P
Save Message as File Ctrl + S
View Message Source Ctrl + U
Select All (messages, text, or attachments) Ctrl + A
Select Thread Ctrl + Shift + A
Toggle Caret browsing (select text with keyboard) F7
Copy selected text Ctrl + C
Cut selected search text Ctrl + X
Paste text into search or filter fields Ctrl + V
Select multiple adjacent messages
(a continuous set of messages) Select the first message of your intended selection, and then
either Shift + Click on the last message of your selection,
or hold Shift while using any of the following movement keys to expand your selection: ↓, ↑, Page Down, Page Up, End, or Home.
Select multiple non-adjacent messages
(several separate messages)
Select any message of your intended selection, and then
either Ctrl + Click on each message that you want to add to your selection,
or hold Ctrl while using any of the movement keys listed below and then pressing Space on each message that you want to add to your selection. The movement keys are ↓, ↑, Page Down, Page Up, End, or Home.
Copy message to another folder Hold Ctrl while dragging message to destination folder (release mouse button before releasing Ctrl).
Move message to another folder Drag message to destination folder.
Move/Copy message to previous target folder Again Ctrl + Shift + M
Archive Message A
Delete message, folder, attachment, or selected search text Del
Delete message bypassing trash (no Undo!) Shift + Del
Undo Ctrl + Z
Redo Ctrl + Y
Rename Folder F2
Tagging and marking your messages
Add/Remove Tag 1 to 9
Remove All Tags from Message 0 (zero)
Mark Message as Read/Unread M
Mark Thread as Read R
Mark All Read Shift + C
Mark as Read By Date C
Mark as Junk J
Mark as Not Junk Shift + J
Add/Remove Star S
Search All Messages (global fulltext search in all accounts) Ctrl + K
Quick Filter (search messages in current folder or view) Ctrl + Shift + K
Clear current Quick Filter; hide Quick Filter Bar Esc (as often as needed)
Search Messages (advanced search in folder) Ctrl + Shift + F
Search All Messages (global fulltext search in all accounts) Ctrl + K
Quick Filter (search messages in current folder or view) Ctrl + Shift + K
Clear current Quick Filter; hide Quick Filter Bar Esc (as often as needed)
Search Messages (advanced search in folder) Ctrl + Shift + F
Finding text in the current message
Find Text in Current Message Ctrl + F
Find Again in Current Message Ctrl + G
F3
Find Previous in Current Message Ctrl + Shift + G
Shift + F3
Go to Mail Start Page Alt + Home
Scroll Down Current Message, then Go to Next Unread Message Space
Go to Next Message F
Go to Previous Message B
Go to Next Unread Message N
Go to Previous Unread Message P
Go to Next Unread Thread (and mark current thread as read) T
Go to Next Viewed Message ]
Go to Previous Viewed Message [
Controlling Thunderbird windows and tabs
Move to next UI element Tab
Move to previous UI element Shift + Tab
Move to next main UI area
In the Mail tab, switch fast between Folder Pane, Message List, Message Pane, and Spaces Toolbar (forwards). F6
Ctrl + F6
Move to previous main UI area
In the Mail tab, switch fast between Folder Pane, Message List, Message Pane, and Spaces Toolbar (backwards). Shift + F6
Ctrl + Shift + F6
Next Tab Ctrl + Tab
Ctrl + Page Down
Previous Tab Ctrl + Shift + Tab
Ctrl + Page Up
Mail & Newsgroups Home Tab (Tab 1) Ctrl + 1
Tab 2 to 8 Ctrl + 2to8
Last Tab Ctrl + 9
Address Book Ctrl + Shift + B
Saved Files Ctrl + J
Help F1
Developer Tools Ctrl + Shift + I
Toggle Message Pane F8
Toggle Menu Bar (if hidden) Alt
F10
Show context menu Menu key
Shift + F10
Minimize current window Win + ↓
Hide Thunderbird (Mac only)
Hide Other Windows (Mac only)
Close window or tab Ctrl + W
Alt + F4 (only for closing a window}
Ctrl + F4 (only for closing a tab)
Undo close tab (restore and go to most recently closed tab) Ctrl + Shift + T
Quit Thunderbird (Exit Application) File, Exit
New message (see Starting a new message) Ctrl + N
Ctrl + M
Save Draft Ctrl + S
Print Draft Ctrl + P
Send Message Now Ctrl + Enter
Send Message Later Ctrl + Shift + Enter
Controlling the compose window
Toggle Contacts Sidebar F9
Move to next main UI element F6
Ctrl + F6
Ctrl + Tab
Move to previous main UI element Shift + F6
Ctrl + Shift + F6
Ctrl + Shift + Tab
Zoom In Ctrl + +
Ctrl + =
Ctrl + scroll wheel up
Zoom Out Ctrl + -
Ctrl + scroll wheel down
Reset Zoom Ctrl + 0 (zero)
Toggle Attachment Pane Alt + M New in TB 60
Show Main Mail Window (Mail & Newsgroups) Ctrl + 1