As a long-time Thunderbird user with years of experience managing desktop email setups, I know how frustrating it can be when software updates alter familiar behaviors. Recent Thunderbird versions have changed the Enter key in the email composer from creating single line breaks to double-spaced paragraphs—a common complaint among users.
To restore the classic single-spacing behavior:
1. Open Thunderbird and go to Tools > Options (or Thunderbird > Preferences on macOS).
2. Select the Composition tab, then click General.
3. Uncheck the box labeled "When using paragraph formatting, the Enter key creates a new paragraph."
That's all! Pressing Enter now inserts a single line break, just like before. This tweak maintains clean, professional email formatting without extra effort.
Prefer double spacing or single? Let us know in the comments below.
