How to Change the Default Font in Outlook (And What It Actually Controls)
If you've ever opened a new email in Outlook and immediately reached for the font toolbar to switch away from Calibri 11pt, you've already spotted the problem. Outlook's default font settings apply globally — but "globally" comes with a few important asterisks depending on which version you're using, what type of message you're composing, and whether you're working in the desktop app or on the web.
Here's what actually changes when you update your default font, and what determines whether the result looks the way you expect.
What "Default Font" Means in Outlook
Outlook separates font settings by message type. Your default font for a brand-new email is not automatically the same as your default font for replies and forwards. This catches a lot of people off guard.
There are three distinct font contexts Outlook lets you configure:
- New messages — the font used when you compose a fresh email
- Replying and forwarding — the font used when you respond to existing threads
- Plain text messages — a separate font setting for emails that don't use HTML formatting
Changing one doesn't change the others. Most users want to update all three, but the process runs through the same settings panel.
How to Change the Default Font in Outlook Desktop (Windows)
This applies to Outlook as part of Microsoft 365, Outlook 2021, 2019, and 2016. The path is the same across these versions.
- Open Outlook and go to File → Options
- Select Mail from the left sidebar
- Under the Compose messages section, click Stationery and Fonts
- You'll see three tabs — Personal Stationery is where font settings live
From the Personal Stationery tab:
- Click Font under New mail messages to set the font for original emails
- Click Font under Replying or forwarding messages to set that separately
- Optionally, adjust the Composing and reading plain text messages setting at the bottom
Each Font button opens a standard font dialog where you can choose the typeface, style (regular, bold, italic), size, and color. Click OK through each dialog to save.
✅ Changes take effect on the next new message or reply you open — existing draft windows won't update automatically.
How to Change the Default Font in Outlook on Mac
Outlook for Mac handles this differently from the Windows version.
- Open Outlook and go to Outlook → Preferences (from the menu bar)
- Select Fonts
- You'll see separate fields for HTML messages and Plain text messages
Click Choose next to each to open a font picker. Unlike Windows, Outlook for Mac uses the native macOS font panel, so the interface looks different but the principle is the same. Set your preferred font, size, and color for each message type.
How to Change the Default Font in Outlook on the Web (OWA)
Outlook on the web (used through a browser, often for work or school Microsoft 365 accounts) has more limited font customization compared to the desktop apps.
- Click the Settings gear icon (top right)
- Select View all Outlook settings
- Go to Mail → Compose and reply
- Under Message format, you'll find a basic text formatting toolbar where you can set the default font, size, and color
The web version doesn't separate new messages from replies in the same granular way the desktop app does. What you set here applies broadly to your composed messages in that browser session and account.
The Variables That Affect Your Results 🖊️
Simply setting a font preference doesn't guarantee every recipient sees exactly what you do. Several factors shape the actual outcome:
| Variable | What It Affects |
|---|---|
| Message format (HTML vs Plain Text) | Plain text emails ignore font settings entirely |
| Recipient's email client | Some clients override sender fonts with their own defaults |
| Custom themes or stationery | Stationery templates can override font settings |
| Corporate email policies | IT-managed accounts may restrict or override font preferences |
| Signature fonts | Email signatures have their own separate font settings |
HTML format is where your font choices actually render. If you or the recipient is set to plain text, font styling is stripped out. Outlook's default message format (HTML, Rich Text, or Plain Text) is set separately under File → Options → Mail → Compose messages.
Signatures Are a Separate System
A common point of confusion: your email signature has its own font settings, independent of the default message font. If you change your default font but your signature was created with a different font, the two can visually clash in the same email.
To update your signature font, go to File → Options → Mail → Signatures, select the signature you want to edit, and reformat the text directly in the signature editor.
When the Font Doesn't Seem to Stick
If your default font keeps reverting or doesn't apply as expected, a few things are worth checking:
- Account type: Some features behave differently for Exchange, IMAP, and POP3 accounts
- Admin policies: Work accounts managed through Microsoft 365 admin settings can lock or override local preferences
- Cached settings: Closing and fully restarting Outlook (not just the compose window) sometimes resolves display glitches
- Stationery conflict: If a stationery theme is active under Personal Stationery, it can override your font choice for new messages
What This Looks Like Across Different Setups 🖥️
A solo user running personal Outlook on Windows with full local control will have a straightforward experience — set the font once, it sticks. A user on a corporate Microsoft 365 account accessed through both the desktop app and Outlook Web App may find settings don't sync between the two, because OWA and the desktop client maintain separate preferences. Someone on a Mac using Outlook alongside Apple Mail may notice the font rendering looks different across clients, since macOS and Windows handle typeface rendering differently at the system level.
The right approach for each of those users isn't identical — even though the underlying goal (a consistent, readable default font) is exactly the same.