How to Fix Spell Check in Outlook (and Turn It On)
If Outlook stopped flagging your typos, the fix depends on your version. In classic Outlook for Windows, spell check is controlled under File > Options, and the most common cause is that “Check spelling as you type” got turned off. In New Outlook for Windows and the web, spelling is handled by Microsoft Editor, a completely different engine you enable from the compose window — so classic instructions won’t apply. A wrong proofing language is the other frequent culprit: if it’s set to Spanish, English errors sail through.
Here’s how to turn spell check on and fix it in every version of Outlook in 2026.
1. Classic Outlook for Windows
Classic Outlook uses the same Office proofing engine as Word, configured in two places.
Turn on check-as-you-type (red squiggles)
- Go to File > Options > Mail.
- Click Editor Options (in some builds this is Spelling and Autocorrect).
- Select Proofing on the left.
- Under When correcting spelling in Outlook, tick:
- Check spelling as you type
- Mark grammar errors as you type (optional)
- Make sure Hide spelling errors is not ticked.
- Click OK.
Red squiggles should reappear under misspelled words as you compose.
Turn on check-before-sending
To force a spell check every time you send:
- Go to File > Options > Mail.
- Under Compose messages, tick Always check spelling before sending.
- Click OK.
Now Outlook runs a full spell check the moment you click Send, catching anything you missed.
Tip: You can run a manual check any time with F7, or Review > Spelling & Grammar.
2. New Outlook for Windows & Outlook on the Web
This is where most “spell check suddenly stopped working” confusion comes from. New Outlook does not use the classic Office proofing engine — there’s no File > Options > Mail > Proofing. Instead it uses Microsoft Editor, the same web-based checker as Outlook on the web.
Enable spelling and grammar in Microsoft Editor
- Open a new message.
- On the compose toolbar, click the Editor button (a pen/checkmark icon) — or open the More options (…) menu and find Editor.
- In the Editor pane, make sure Spelling and Grammar checks are turned on.
You can also check the account-wide setting:
- Click the Settings gear (top right) > General.
- Look under Spelling & grammar (it may sit under Editor depending on your build) and confirm Show spelling/grammar suggestions is enabled.
Because the checker is browser/Editor-based, suggestions appear as you type and on demand from the Editor pane — there’s no separate “check before sending” toggle the way classic Outlook has.
Note: If you previously relied on Always check spelling before sending, that exact option doesn’t exist in New Outlook. Use the Editor pane to review before sending, or keep classic Outlook if you depend on that behavior.
3. Outlook for Mac
- With a message open, go to Outlook menu > Settings > Spelling & Grammar (or Tools > Spelling and Grammar depending on build).
- Tick Check spelling as you type and Check grammar with spelling.
- To check before sending, look for Check spelling as you type plus the manual Edit > Spelling and Grammar > Check Document Now.
Mac Outlook also respects the system-wide macOS spelling settings, so if nothing is flagged, check System Settings > Keyboard > Text Input > Edit > spelling options.
4. Fix the Proofing Language (the silent culprit)
A huge share of “spell check not working” cases are really wrong-language problems: Outlook is checking against, say, Spanish or English (UK) while you’re writing in English (US), so it misses or mis-flags words.
Classic Outlook for Windows
- In the message, select the text (or Ctrl+A for all of it).
- Go to Review > Language > Set Proofing Language.
- Choose the correct language, e.g. English (United States).
- To make it stick, click Set As Default (applies to new messages).
- If Outlook keeps switching languages, untick Detect language automatically — auto-detect is the usual reason proofing flips to the wrong language mid-message.
New Outlook / Web
- Open the Editor pane in a message.
- Use the proofing language selector in that pane to set the language for the message.
- Account language lives under Settings > General > Language and time.
Outlook for Mac
Select the text, then Edit > Spelling and Grammar doesn’t set language directly — instead go to the macOS System Settings spelling list and add/prioritize your language, or set it in the message’s language picker.
5. Clear “Do Not Check Spelling” on a Single Message
If spell check works everywhere except one message (or text pasted from elsewhere), that text likely has the “Do not check spelling or grammar” flag set.
Classic Outlook:
- Select the affected text (Ctrl+A for the whole message).
- Go to Review > Language > Set Proofing Language.
- Untick Do not check spelling or grammar.
- Click OK.
This flag often rides along when you paste text from a web page or a document that had it set. Reselecting the language clears it.
Troubleshooting
Outlook spell check not working at all (classic)
Confirm Check spelling as you type is on under File > Options > Mail > Editor Options > Proofing, and that Hide spelling errors is unticked. If it’s still dead, the message text may carry the Do not check spelling flag — reselect the proofing language to clear it.
New Outlook spell check not working
New Outlook uses Microsoft Editor, not the classic engine. Open a message, click the Editor button, and turn on Spelling and Grammar. There’s no File > Options > Proofing in New Outlook — looking for it is why it seems “broken.”
Spell check is greyed out
This usually means a language/proofing tools problem or the text is flagged Do not check spelling. Select all text, set a valid proofing language, and untick Do not check spelling or grammar. In classic Outlook, also make sure proofing tools for that language are installed (File > Options > Language).
Red squiggles disappeared
Hide spelling errors got ticked, or check-as-you-type was turned off. Re-enable both under Proofing (classic) or the Editor pane (New Outlook).
Checking in the wrong language (e.g. flagging English as Spanish)
The proofing language is set wrong, or Detect language automatically flipped it. Select the text, set Set Proofing Language to your language, click Set As Default, and untick auto-detect.
Spell check before sending isn’t running
In classic Outlook, tick Always check spelling before sending under File > Options > Mail. New Outlook has no equivalent — review in the Editor pane before you send, or use classic Outlook.
Quick Reference
| Setting | Classic Outlook (Windows) | New Outlook / Web | Outlook for Mac |
|---|---|---|---|
| Check as you type | File > Options > Mail > Editor Options > Proofing | Editor button in compose | Settings > Spelling & Grammar |
| Check before sending | File > Options > Mail > Always check spelling | Not available (use Editor pane) | Manual check |
| Set proofing language | Review > Language > Set Proofing Language | Editor pane language selector | macOS / message language picker |
| Clear “Do not check spelling” | Review > Language > untick option | Reselect text in Editor | Edit > Spelling and Grammar |
| Manual check | F7 / Review > Spelling & Grammar | Editor pane | Edit > Spelling and Grammar |
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More on Outlook: How to change the language in Outlook · How to create an email template in Outlook · How to add a signature in Outlook · How to recall an email in Outlook · How to schedule an email in Outlook · How to clean up your inbox in Outlook
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