If the text box won't resize in Word or Excel, check if the document is opened in the Compatibility Mode, and convert it to a newer format.

Click "OK" to close the Envelope Options box. The Envelopes and Labels dialog box will show the updated font size on the Delivery Address section and the Return Address.

Microsoft Office offers an easy way to change default font via settings. Learn how to change the default font in Word, Excel & PowerPoint.

Customize Word’s font settings to your liking, whether you’re a Times New Roman traditionalist or totally fluent in Wingdings.