That warning is based on the content and structure of the email. There is no whitelist of good guys.

On the toolbar >Options > security > scams and urn it off if you do not care your correspondents are using privacy invading tricks that trigger the warning.

No wonder I almost always get this red bar about a scam. Even your Mozilla email message had the red bar suggesting you're a possible scam. When I clicked to be able to post this note, I got the following message: "Thunderbird thinks this message is a scam. The links in the message may be trying to impersonate web pages you want to visit."

Getting this red bar warning has been a sudden and recent thing. . .coming up on emails from people and places who send them often. It's weird!!!

Is anything now adding comments to your incoming messages? One of the triggers for a scam warning is a mix of URLs in a message.

Robot replies don't help answer my question. I'd like a phone number so I could ask a person.

Here is another robot answer: Does your email-server-provider mark them as scam?

Walmar said

Robot replies don't help answer my question. I'd like a phone number so I could ask a person.

As the code that manages scam detection has seen no edits in recent years then it is not new, even if you think it is. So you have your answer. Turn it off if your do not like it's choices. I gave you the information to do that in my initial reply.

BTW as the Thunderbird council has no funds or employees, there is no office and ipso facto no phone. Think yourself lucky Mozilla sees fit to allow the use of their infrastructure and to use this forum.