Mail chimp uses just about every scammy thing they can, right down to web bugs to see who opens the mail and where they are. (Best not to enable images on mailchimp generated mails)

The newsletter from MailChimp is sent to contacts who have signed up themselves and it comes from a known sender. They also have the option to stop receiving the newsletter by clicking on unsubscribe. They can edit their own information recorded on the newsletter. Such newsletters are quite harmless and that the recipient have the opportunity to choose whether they want it or not. Then I do not know why Thunderbird has chosen to put this on their scam list and realize nor argument that one can see who opened your newsletter?

It is of course important for the sender to know whether the information in the newsletters are received and read. By comparison are retargeting very common to use on websites and is also a form of tracking user. Of this policy should then Firefox have marked quite a few sites as scams too...

Other emails, which are obviously scams, release easily through in Thunderbird without being marked. Even obvious phishing attempts. But when it comes MailChimp then there is the pre-selected to define everything as scams and this I think is very unfortunate.

Great, but your working from two misconceptions.

1. There is no scam list... there are actions in the mailing that triggers the warning. They are simple

• Links that only use an IP address, including dotted decimal, octal, hex, dword, or some mixed encoding.
• Links that claim to go to one site, but actually go to another. (Phishers do this to fool you into going to their site. Legit mailing lists sometimes do this with redirectors for tracking purposes.)
• Forms embedded in the email. (This explains the LiveJournal notices.)

Refrain from those actions and your mail will not be detected.

2. What you as the sender consider important. I as the recipient consider an invasion of my privacy. When you send me marketing stuff snail mail you get zero feedback unless I contact you. The fact that marketers think they are entitled to anything more from email is unfortunate. In my view they are not.

Source code: http://mxr.mozilla.org/comm-central/source/mail/base/content/phishingDetector.js

1. Ok - I´ll then remove all links and see if that helps.

2. You are missing the important point that the users has signed up for this newsletter and that they also can unsubscribe. Therefore I mean that you can not compare this with marketing stuff you get as snail mail.

And back to remarketing (retargeting) on websites that shows you relevant ads in other websites because you have been on a particular website. Wouldn't that also then be an invasion of your privacy in your (or Mozillas) opinion? Should not Mozilla (Firefox) then warn the user that the site they are visiting could be unsafe/scam/spam?