Switch Between HTML And Plain Text Emails In Thunderbird

Emails can be composed as HTML or plain text messages. HTML emails mainly offer the advantage of better formatting options over plain text emails from a user's point of view. Internet marketers and companies may use them for tracking purposes.
HTML emails support text formatting options such as changing the font size, using bold or underline, displaying lists or images. While that is great to make emails look prettier, the downside is that HTML emails pose security and privacy risks.
It is for instance possible to embed an - often invisible 1x1 pixel image - in the HTML email to track if the recipient has read the email (opened it). There have also been cases where maliciously modified objects were included in emails.
The Thunderbird email client supports both plain text and HTML emails. The account settings hold the default preference for each email account in the mail client. This only affects email messages that are created in Thunderbird, not messages that are received.

You open the Account Settings with a click on Tools > Account Settings. If the menu bar is not displayed by default, unhide it with a tap on the Alt-key on the keyboard.
Go to Composition & Addressing, and check or uncheck the "Compose messages in HTML format" option there.
The preference for incoming emails is found under View > Message Body As. Here it is possible to switch from the default Original HTML to Simple HTML or Plain Text.

This preference is valid for all incoming emails, regardless of the email address they have been sent to.
Original HTML
Original HTML displays emails as HTML messages. This may include that images do get downloaded from remote servers (something that trackers often do) and that JavaScript may be executed.
Thunderbird users may disable remote content in messages in the Options under Privacy > Allow remote content in messages.
If you choose View – Message Body As – Original HTML, then you see HTML messages in their original form.
Simple HTML
Simple HTML takes the best of both worlds. It preserves the formatting of HTML emails but blocks JavaScript code and remotely downloaded images.
If you choose View – Message Body As – Simple HTML, then you see HTML messages in a simplified form. Thunderbird does not run JavaScript code, and does not download remote images. Simple HTML preserves basic HTML formatting.
Plain text
If you select plain text as the view option in Thunderbird, all emails are displayed as plain text. This is true even for messages that were sent as HTML emails.
If a message is multi-part, only the plain text part is displayed. Note that Thunderbird may enhance plain text messages with certain text formatting features such aa:
- Bold, italic and underlined text.
- Smileys displayed as images.
- Attached images displayed in the body of the message.
- Links displayed in blue, and underlined.
- Flowed paragraphs (if the message was sent using flowed paragraphs)
- Quoted paragraphs outlined with colored bars (if the message was sent using flowed paragraphs)
- Signatures displayed in gray.
The supported smileys are:
:-) :) smile
:-D laughing
:-( :( frown
:-[ embarassed
;-) ;) wink
:-\ undecided
:-P ;-P tongue
=-O surprise:-* kiss
>:o >:-o yell
8-) cool
:-$ money
:-! foot
O:-) innocent
:'( cry
:-X sealed
It sometimes may be necessary to write HTML emails and plain text emails, depending on the recipient. While it is possible to switch the format in the account settings, it is possible to make a temporary switch when composing emails.
Holding down the Shift key before clicking on create a new message, or one of the reply options, switches from the default writing mode to the other.
Thunderbird will automatically display the plain text email editor if HTML emails are the default, and vice verse if the Shift key is pressed.
The composition window will display HTML elements like bold or underline if an HTML message is composed, or no text formatting options if it is a plain text email.
HTML Email composition window

Plain Text composition window

Holding down the shift key is the fastest way of switching between HTML and plain text composition windows.
Please note that the Shift-key modifier works only if you click on the write or reply buttons in the Thunderbird interface. It does not work if you use keyboard shortcuts such as Ctrl-N.


You said that Outlook isn’t your main email client, so which is your main one?
I think its thunderbird
It is Mozilla Thunderbird.
Awesome! This actually solved my problem… what a stupid bug.
If this is the same bug that I’ve encountered, there may be another fix: (1) hover over open Outlook item in Taskbar, cursor up to hover over Outlook window item, and right-click; (2) this should give you Restore / Move / Size / Minimize / Maximize — choose Move or Size; (3) use your cursor keys, going arbitrarily N/S/E/W, to try to move or size the Outlook window back into view. Basically, the app behaves as though it were open in a 0x0 window, or at a location that’s offscreen, and this will frequently work to resize and/or move the window. Don’t forget to close while resized/moved, so that Outlook remembers the size/position for next time.
THANK YOU Claude!!! I could get the main window to launch but could not get any other message window to show on the desktop. You are my hero!!!!
Solved my issue! 6 years later and this is still problem…
Fantastic. Thank you. Size did the trick.
This solved my Outlook problem, too. Thank you. :)
Thank you so much, this started happening to me today and was causing big problems. You are a life saver, I hope I can help you in some way some day.
You are a god – thank you!
thanks a lot…. work like charm.. :-)
Yah…thanks Claude. I’ve been having the same problem and tried all the suggestions…your solution was the answer. It had resized itself to a 0/0 box. Cheers
Excellent post. This had me baffled even trying to accurately describe the problem. This fixed it for me.
Thank you
Thanks a lot for the article. Don’t know why it happenend, don’t know how it got fixed, but it was really annoying and now it works :-)
Thanks a lot. I was facing this issue from past 3 week. I tried everything but no resolution. The issue was happening intermittently and mainly when I was changing the display of screen ( as i use 2 monitors). The only option i had was to do system restore. But thanks to you.
I’ve been tried to sole this problem for 12hours. Your comment about changing the display of screen helped me a lot!! Thanks!!
Thank you…don’t know why this happened but your instructions helped me fix it. Running Windows 10 and office pro 2007
Great tip! Thanks!
Worked for me, too – thank you!!!
It’s Worked for me, too
thank you very much!
I had a similar issue with Outlook 2013 on Windows 10 and this helped me to fix it. Thank you very much!
Thank you so much. Solved!
Considering you published this in 2012, incredible not been debugged by Microsoft.
Thank you again. M
This problem was faced by only one user logging to TS 2008 r2 using outlook 2010.The issue was resolved.
Thanks.
Great tip. Thank you!!!! If it helps, I had to use the Control Key and the arrow keys at the same time to bring my window back into view. Worked like a charm.
Thank you, this worked !!!!
Man, you are a fucking god. Thanks a lot, what an annoying bug!!
Awesome, this post solved the issue. Many thanks!