Why is the font in my emails suddenly different?

Check your email client settings
If you’re using an email client such as Outlook, Thunderbird, or Apple Mail, check the font settings in those programs to make sure the font you prefer is selected.
Check your operating system
If you’re using a Windows PC, check the Windows Color and Appearance settings. On a Mac, go into System Preferences and check the General font settings.
Check your web browser
If you’re reading your emails in a web browser, such as Chrome or Firefox, check the font settings. Some browsers allow you to set a default font for all websites.
Check if you’ve made changes
See if you can recall any changes you recently made to your computer. If you’ve installed a new font, it might be the source of the sudden change.
Check your website security settings
If you’ve adjusted the security settings on your browser, it could be blocking certain font styles from being displayed.