Starting suddenly on Thursday, every email I've sent to a gmail address has been marked a spam, even to people who I've been emailing with for years, who have me in their addressbook. Gmail gives them this message:
Lots of messages from messagingengine.com were identified as spam in the past.
What the heck? Is this happening to others? How do we stop it?
Screenshot of gmail message:
https://imgur.com/a/ulMMM0I