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jsarah
Staff
Staff
February 26, 2026

Troubleshooting Tip: Difference in FortiSASE DLP action when using SSL/TLS and STARTTLS in Outlook

  • February 26, 2026
  • 0 replies
  • 135 views
Description This article describes the behavior of DLP in FortiSASE when different protocols are used in Outlook.
Scope FortiSASE.
Solution

If the Outlook application settings are the ones shown in Screenshot 1 below, FortiSASE will remove the attachment and send the email to the recipient. The sender will not receive any intimation suggesting a violation of any policy. The encryption method used in this case is SSL/TLS.

 

However, if the application settings are the ones shown in Screenshot 2 below, FortiSASE will block the message and inform the sender that the email has been blocked because it violates the network policy. The encryption method used in this case is STARTTLS.

 

This behavior can be observed in the DLP logs in FortiSASE as shown below:

 

Screenshot 2026-02-20 170600.png

 

Screenshot 1:

 

Kishor_SMTP_configuration.png

 

Screenshot 2:

 

Rohan_SMTP_configuration(1).png

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