I have a friend who is something of a public figure within a small sphere. She has been an object of negative attention recently in this sphere and has noticed that her emails are suddenly all going directly into the Spam folders of all her recipients. This holds true even amongst recipients on different emails services, and she has been using this email address for years without any problems.
I ask her to send an email to Mail Tester and you can see the results here (10/10 for email quality). She uses a very well known email hosting solution with a custom domain name. According to a source, she heard that apparently someone somewhere did something so that her emails would get sent to Spam.
For a particular email provider, I could sort of understand how this could work (imagine someone malicious working on the inside at Google), but I can’t see how this could be the case otherwise. It’s even stranger considering that some of her recipients have added her address to their whitelist and clicked on the “Not spam” button several times (in Gmail for example).
Is what my friend fears possible? If so, how?