Outlook has one Junk Email Filter with four protection levels. Microsoft sets the default level to No Automatic Filtering so you raise it yourself. Open Home, Block and Junk E-mail Options and select Low, High or Safe Lists Only. Add trusted addresses to Safe Senders and spam addresses to Blocked Senders. Check your junk folder for real messages.
Spam arrives every day and the filter seems to do nothing. Microsoft documents how the filter works and which level to select.
Facts follow two Microsoft Support pages. One explains the level of protection and the other gives an overview of the filter in classic Outlook. Both pages name Outlook for Microsoft 365, Outlook 2024 and Outlook 2021. Outlook 2019 and Outlook 2016 appear in the overview too. New Outlook for Windows uses a separate Microsoft article.
How does the Junk Email Filter Work?
Delivery continues as normal. Outlook moves suspected spam to a junk folder after it checks the message content and the time it was sent. Microsoft states the filter is on by default and the default level is No Automatic Filtering.
Which Protection Level is Needed?
| Level | What Microsoft says |
|---|---|
| No Automatic Filtering | Turns off automatic filtering. Messages from the Blocked Senders list still go to junk. |
| Low | Suits users with little junk mail who want only the most obvious junk filtered. |
| High | Suits users with a lot of junk mail who still want mail from safe list senders. |
| Safe Lists Only | Most restrictive. Mail from anyone outside Safe Senders or Safe Recipients becomes junk. |
Higher levels catch more junk but move more real messages to the junk folder. Microsoft recommends a regular look at that folder.
How to Set the Level?
- Select Home in Outlook.
- Select Block and then Junk E-mail Options.
- Select the level on the Options tab.
- Select OK.
What are the Safe and Blocked Lists?
- Safe Senders. Listed addresses and domains never go to junk. Contacts can be added. Microsoft gives a limit of 1,024 entries.
- Safe Recipients. Mail sent to a listed address or distribution list never goes to junk.
- Blocked Senders. Listed addresses and domains always go to the Junk E-mail folder.
- Blocked Top-Level Domains. Rejects country or region domains. Listing CA, US and MX rejects .ca, .us and .mx addresses.
- Blocked Encodings. Sends messages in selected character sets or alphabets to junk.
What Differs With Exchange Accounts?
On a Microsoft Exchange Server account every entry in the global address list counts as safe. Exchange Online and Exchange Online Protection do not recognize safe domains by default. They recognize domains and sender addresses on the block list and sender addresses on the safe list.
How to Recover a Real Message From Junk?
Move the message to the Inbox or another folder. You can also select Home, Report and Not Junk in the junk folder.
Microsoft also names a delete option on the Options tab. It deletes suspected junk for good instead of moving it. Microsoft warns that this removes your chance to find false positives.
Related reading: how to encrypt Outlook emails and how to solve a full mailbox in Outlook.
Frequently Asked Questions
What is the Default Junk Email Level in Outlook?
Microsoft states the default level is No Automatic Filtering.
How do I Stop Real Mail Going to Junk?
Add the sender to Safe Senders. Move a wrongly filed message to the Inbox or select Not Junk.
How Many Addresses Fit in Safe Senders?
Microsoft gives a limit of 1,024 entries.
Is Safe Lists Only the Strictest Level?
Yes. Mail from anyone outside Safe Senders or Safe Recipients is classified as junk.
Key Takeaways
- Outlook moves spam to a junk folder and delivery continues.
- No Automatic Filtering is the default level.
- Safe Lists Only is the strictest level.
- Safe Senders take up to 1,024 entries.
- Check the junk folder for real messages.
Sources and References
Facts follow Microsoft Support.
- Level of protection in the Junk Email Filter (Microsoft Support) support.microsoft.com
- Junk Email Filter overview for classic Outlook (Microsoft Support) support.microsoft.com