How to change the default font in Outlook on Mac: new and legacy steps

Changing the default font in Outlook for Mac is a short job once you know where the setting lives. The catch is that Outlook for Mac now runs in two versions, and each hides the setting in a different menu. Microsoft's support pages cover both, so the steps below follow its paths and flag where the names differ.

Find out which Outlook for Mac you use

Look at the top-right corner of the Outlook window. If you see a Legacy Outlook toggle, check whether it is on. SMU IT says a toggle that is on means you opted into legacy Outlook. Microsoft's page calls the two versions Outlook for Mac and Legacy Outlook for Mac.

Microsoft does not publish build numbers for these versions. You cannot match your build to a version table, so the toggle and the menu names are your best clues. If your menus match one of the paths below, follow that path. If they do not, try the other one.

• New Outlook for Mac: open Outlook > Settings > Composing for the default font.
• Legacy Outlook for Mac: open Outlook > Settings > Fonts.
• Some older builds use Outlook > Preferences > Font instead. A 2023 Microsoft Q&A thread reports this path, and a moderator says some builds use it.

Decide what you want to change first

Before you open any menu, decide three things. Pick the font, pick the size, and decide whether replies should match new mail. Those three choices map to different settings, so writing them down saves time.

In new Outlook for Mac, mail you start and mail you answer are separate settings. If you only change New mail, your replies keep their own font. That split is the most common reason people think the change failed.

Change the default font in new Outlook for Mac

New Outlook for Mac has the cleanest path. Open Settings, go to Composing, and pick a font for each kind of message. The steps in this guide follow Microsoft's page for Outlook for Microsoft 365 for Mac.

Pick a font your recipients can read on a phone. Choose a size that looks normal in the preview, not one that looks oversized. Click OK to save the choice before you close the panel.

Think about who reads most of your mail. A plain sans serif font at a normal size is a safe default for most people. Avoid heavy weights for body text, because long messages get tiring to read.

If the font panel will not keep a variant, choose the regular weight of the same family. That is the safest option in new Outlook for Mac right now, given the known issue covered further down this page.

Change the default font in legacy Outlook for Mac

Legacy Outlook for Mac keeps fonts on its own Settings page. It sets one font for each style, so you repeat the steps for every style you want to change. Microsoft's page names this area Default fonts.

1. Choose Outlook > Settings. Older builds may show Outlook > Preferences instead.
2. Click Fonts in the Settings window.
3. Under Default fonts, click the Font button beside New mail.
4. Pick a font and a size in the font panel.
5. Optional: open the Advanced tab to change scale, spacing or effects.
6. Click OK, then repeat for any other style you want to change, such as replies.

The Advanced tab holds scale, spacing and effects. Leave those alone unless you have a specific reason. They change how text looks as you type, so a small change can make every message feel different.

Microsoft's page does not mention copying settings between the two versions. Plan on setting the font again in whichever version you use every day. Check the version name first, because the steps differ.

Set the default font in Outlook on the web

If the font list in the Mac app does not offer what you need, Microsoft points people to Outlook on the web. The web settings sit in a different place, so follow these steps in your browser.

1. Open Settings in Outlook on the web, then choose Mail > Compose.
2. Under Message format, set Compose messages in to HTML. Microsoft says fonts only work in HTML.
3. Choose the default font and size.
4. Select Save.

Microsoft's web article does not describe a separate font for replies and forwards. Treat the web setting as one default for everything you write there.

The web route is also the fallback when a Mac setting will not save. A Microsoft Q&A thread suggests it, and this guide did not test it. Send yourself a sample message from the Mac app to confirm the font shows up.

Keyboard shortcuts and what they do not change

No keyboard shortcut changes the default font in Outlook for Mac. Microsoft's Mac shortcut page lists none for this job. The shortcuts below still help when you write a message, but they only change selected text or the view.

• ⌘ , opens the settings window. Microsoft's shortcut page calls it Preferences.
• ⌘ B, ⌘ I and ⌘ U apply bold, italic and underline to selected text.
• ⇧ ⌘ X applies strikethrough to selected text.
• Format > Increase Font Size and Format > Decrease Font Size change the whole folder view.
• Format > Zoom changes the view of a single email.

A common mistake is to select text, make it bold, and expect Outlook to remember it. It will not. Selected formatting only applies to that text. The default lives in Settings, so change it there.

Known issues and a date to watch

Two problems come up often enough to plan around. The first is font variants. A Microsoft Q&A answer posted November 4, 2025 says new Outlook for Mac cannot set variants such as Light or Bold as the default through the selection menu. Calibri Light still shows while you compose, and Microsoft has no timeline for a fix.

The second is the legacy end date. Microsoft says support for legacy Outlook for Mac ends in October 2026. SMU IT says legacy Outlook stops connecting on October 1, 2026, and then shows no email, no calendar and no contacts. That date is now in the past. Neither source confirms whether it was enforced or moved, so check Microsoft's current notice before you rely on legacy steps.

A June 16, 2026 Microsoft Q&A thread reports that search, rules and junk-mail reporting stopped working for some people who moved to new Outlook for Mac. No Microsoft staff reply appears in that thread. Test your rules and search before you depend on them.

The Calibri Light thread suggests Outlook on the web as a workaround. This guide did not test that workaround, so send yourself a test message first.

Mistakes people make with default fonts

• Changing New mail and expecting replies to follow. In new Outlook, Reply or forward has its own Select button.
• Selecting text and expecting the default to change. Selected formatting only applies to that text.
• Hunting for a shortcut. Microsoft lists none for default fonts.
• Following legacy steps in new Outlook, or the reverse. Check your version first.
• Setting a font on the web without switching to HTML. Fonts only work in HTML.
• Forgetting signatures after a switch. SMU IT advises checking them under Outlook > Settings > Signatures.

A worked example for a small office

Say you run a small office and send quotes to clients all day. You want new mail in a clean sans serif font that reads well on a phone. Replies can keep the font your team already uses, so only the New mail setting changes.

Open Outlook > Settings > Composing. Click Select beside New mail, choose the font and size, and click OK. Then send a test message to yourself and open it on your phone. If the text looks too small, go back to the Font panel and try one size up.

If you use a signature, check it after you change the font. SMU IT advises checking signatures after you switch versions. For setup steps, see how to create an email signature in Outlook on Mac.

A worked example for a reply-heavy inbox

Now take a different case. You mostly answer messages from clients, and you rarely start new ones. In this case, set Reply or forward first, because that is the font you will see most often.

Open Outlook > Settings > Composing, click Select beside Reply or forward, and choose the font. Click OK. Then answer a message that you received last week and check that the font in the reply body matches what you picked.

Check the change before you rely on it

Start a new message and look at the font in the body before you type. Then reply to an older email and check the reply font. If a change does not show up, quit Outlook and open it again.

If the old font still appears, clear the Outlook cache. The Calibri Light Q&A thread suggests that step too. Then open Settings and check the setting again. Keep a test message in your drafts so you can repeat the check after updates.

Next steps

• Create an email signature in Outlook on Mac once your font is set.
• Turn on automatic replies in Outlook on Mac for days you are away.
• Create a folder in Outlook on Mac to keep client mail in one place.