High "High-Risk" percentage of outbound mails

Copper Contributor



Situation: We have a high "High-Risk" percentage (60%-80%) of outbound mails from our domains in exchange. We don't use third-party tools to mass send mail and are wondering why this is happening.


How can we see what kind of mails get the high-risk flag and how can we reduce this percentage drastically, to prevent our mails get marked as potential spam.

1 Reply

Hi @JChristiansen,

To reduce the "High-Risk" percentage of outbound mails in Exchange, you can follow these steps:

1. Configure Outbound Spam Policies: In Microsoft 365 organizations with mailboxes in Exchange Online or standalone Exchange Online Protection (EOP) organizations without Exchange Online mailboxes, outbound email messages that are sent through EOP are automatically checked for spam and unusual sending activity. You can configure outbound spam policies in the Microsoft 365 Defender portal or in PowerShell.

2. Add Users to Sender Allow List: Go to Exchange admin center (EAC) with admin’s credential. Navigate to Protection > spam filter. Choose the policy whose the priority is lowest and click allow lists. Add the user into sender allow list and save.

3. Modify Anti-Spam Settings: Go to Threat Management - Policy - Anti Spam settings - (scroll down) Allow list - Allow Sender - Edit the list.

4. Uncheck "Send a copy of suspicious outbound messages": Go to Anti-Spam outbound policy (Default) and uncheck "Send a copy of suspicious outbound messages" then click 'Save'.

You can use these links for more information:
(1) Configure outbound spam policies | Microsoft Learn.
(2) https://answers.microsoft.com/en-us/msoffice/forum/all/cant-prevent-user-sending-via-high-risk-deliv....
(3) https://community.spiceworks.com/topic/2195403-outbound-email-marked-as-spam.
(4) https://security.microsoft.com/antispam.
(5) Microsoft disables bad spam rule flagging all sent emails as junk. https://www.bleepingcomputer.com/news/microsoft/microsoft-disables-bad-spam-rule-flagging-all-sent-e....
(6) High "High-Risk" percentage of outbound mails - Microsoft Community Hub. https://techcommunity.microsoft.com/t5/exchange/high-quot-high-risk-quot-percentage-of-outbound-mail....

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Kindest regards,

Leon Pavesic