I need to build a whitelist for my Comcast’s web e-mail account. I need this for a weekly newsletter which keeps on being placed in the Spam folder, no matter what I do. I could not find any advice from Comcast for this issue. I found an old post here with this same question dating from 2017 and the only advice was to "keep making the e-mail 'not spam,'" which I have been doing for several months without any effect. How can I keep this newsletter from being marked as spam?