In order to better research this issue, please provide more information:
What is your Outlook client version? Make sure to update to the latest version.
How did you add to Safe Sender and are there any errors?
Please add the contact to the Safe Senders (Click Home > Delete group > Junk > Junk E-mail Options>Safe Senders>Add), so that email addresses and domain names in the Safe Senders List are never treated as junk email, regardless of the content of the message. More information:
Add recipients of my email messages to the Safe Senders List.
In addition, it is recommended that you could select the trusted spam in the Junk folder and click on the Report Message option and choose Not Junk, which may have an impact on your spam filtering.
Hope this helps!
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