Let’s see how to optimize anti-spam settings in Microsoft 365. Anti-spam settings can be modified from the protection portal of Microsoft 365. By default, this service is available for all Exchange online users.
Login to https://security.microsoft.com
Spam Properties – Increase Spam Core – Turned on below.
- Number of IP Addresses in URL
- URL to biz or info websites
- URL Redirect to other Port
Spam Properties – Mark as Spam – Turned on below.
- Embed tags in HTML
- Form Tags in HTML
- Frame or IFrame Tags in HTML
- Web bugs in HTML
- Object tags in HTML
- Apply sensitive words list.
- SPF Record Hard fail
- Conditional Sender ID filtering – Hard Fail.
- NDR Backscatter.
Default Spam Filter Policy – Edit Policy –
Spam and Bulk actions –
- High Confidence Spam
- Phishing Email
- Bulk Email
All Set to – Move Message to Junk Email Folder
So that all sort of emails are in the junk. As this specific org doesn’t want to release email from quarantine. Please set as per the organization needs.
So far these settings have worked out for me very well , have applied the same in few office 365 tenants.