I use Microsoft Outlook 2019 and the only email that gets sent to the AntiSpam folder is the email when I identify it as spam. This is what Norton says I need to do because my email does not use default ports:
Norton AntiSpam supported protocols and ports
Only POP3 and SMTP protocol is supported.
POP3 with SSL is not supported.
IMAP & Exchange accounts are not supported.
If email client is configured in ports other than default ports 110, then the new port needs to be added to protected ports.
My email uses ports 995 and 465 and when I try to add these to AntiSpam protected ports, I am told that these ports are used by programs other than the supported email programs. It cannot be added to the list of protected email ports.
Ports 995 and 465 are secure and encrypted. So no anti spam feature is able to look inside the incoming email. Your email client can be used to filter for spam.
And any attachments are scanned by other layers of protection in your Norton product as/if you try to access that attachment. Here is a good post by @SendOfJive that explains this. https://community.norton.com/en/comment/8513653#comment-8513653 Although that user is using Thunderbird email client, the information should still apply to Outlook.
Two weeks ago Norton and Microsoft together added an Extention to MS Edge browser for Norton Password Manager. It hasn't been fixed, despite multiple online and Chat assistance. I was told to wait a few days, as the Norton Cloud was the problem. When will it be fixed?