Friday , April 19 2019

Optimize Antispam Settings in Office 365

Lets see how to optimize anti spam settings in office 365. Anti spam settings can be modified from protection portal of office 365.  by default this service is available for all Exchange online users.

Login to

Threat Management  – Policy – Antispam


Turn on the custom policy –


Default Spam Filter Policy – Edit Policy –

Spam and Bulk actions –

  • Spam
  • 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.


Spam Properties –  Increase Spam Core – Turned on below.

  • Number IP Address 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
  • JavaScript or VBscript 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.


So far these settings have worked out for me very well , have applied the same in few office 365 tenants.

About Satheshwaran Manoharan

Satheshwaran Manoharan is an Microsoft Exchange Server MVP , Publisher of
Supporting/Deploying/Designing Microsoft Exchange for some years.
Extensive experience on Microsoft Technologies.

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