Email, Messaging, & Video Calls Email How to Set Mozilla Thunderbird's Default Format Stop Thunderbird from Asking 'Plain Text or HTML'? by Heinz Tschabitscher Writer A former freelance contributor who has reviewed hundreds of email programs and services since 1997. our editorial process Heinz Tschabitscher Updated on October 15, 2019 Janayna Velozo / CC BY-ND 2.0 license Email Yahoo! Mail Gmail Tweet Share Email After hitting send, Thunderbird also wants you to decide whether to send the message as plain text only, HTML, or both - every single time you send a message. Fortunately, Mozilla Thunderbird is not only very flexible and sensible when it comes to formatting messages so that everybody can enjoy them, but it can also be very comfortable and sensible about asking too many questions. Without ever asking you again, Mozilla Thunderbird can deliver all (formatted) messages in both plain text and HTML, for example. Set the default format for emails once in Mozilla Thunderbird, and it will stop you from asking for each message you send. Prevent Mozilla Thunderbird From Inquiring About the Format When Sending To stop Mozilla Thunderbird from asking you about the desired format when you compose a rich text message and click Send: Select Options from the Mozilla Thunderbird (hamburger) menu.You can also select Tools | Options (or Thunderbird | Preferences... on a Mac) from the menu if you see that.Go to the Composition category.Make sure the General tab is selected.Click Send Options…Under Text Format, make sure something other than Ask me what to do is selected. We recommend Send the message in both plain text and HTML, which preserves any rich formatting while giving recipients a chance to choose a plain text alternative. Messages you compose in plain text only will not be converted to HTML.For people you know to disdain all rich formatting (for privacy concerns perhaps), set their preferred format to plain text. This will override your default choice, but only if the message has no other recipients set to accept HTML. Click OK.Close the options window.