New Outlook and Outlook on the web
In new Outlook, open View > View settings, then Mail > Compose. Under Message format, select the font, size and style, then save. On the web, use Settings > Mail > Compose and check the message-format options.
These are composition preferences. Enlarging the Reading pane is a separate zoom task.
Classic Outlook for Windows
Open File > Options > Mail > Stationery and Fonts. On Personal Stationery, use Font under the appropriate new-message or reply-and-forward section. Apply the selections and confirm the dialogs.
New messages and replies can have separate preferences. Review both if you want a consistent composition style.
If the result is not what you expected
For reading size, use the Reading pane’s Zoom controls rather than repeatedly changing the outgoing font. A recipient can see a substitute if the selected family is unavailable to their mail software.
For your own review, compare a new draft and a reply. Keep readable wording and a restrained hierarchy rather than relying on one unusual face to carry the message.
Understand the font you choose
Explore the background of Arial or Calibri when those names appear in your workflow. Our previews do not alter Outlook settings.
For decorative copyable characters, the bold text tool is a separate mechanism from Outlook’s native formatting.
Your questions, answered.
Does Reading pane zoom change my outgoing font?
No. Reading zoom and composition formatting are different controls.
Why does a reply use another font?
Classic Outlook offers separate preferences for new messages and replies or forwards.
Will recipients always see the chosen family?
Not necessarily. Their software may substitute another available font.
Sources & background
Sources supporting this page’s explanations. Practical examples are our editorial suggestions.