Thunderbird email client is a terrific email reader program that can and has helped many schools, businesses and individuals maintain their email on their computers. As SPAM has become more and more difficult to recognize, Thunderbird has turned these filters into very aggressive technology to protect users. Since computer infections can now access and use real email addresses from your personal email address book, sending fake email and attachments, Thunderbird is trying to help users more than cause problems.
The good news is that you can teach Thunderbird junk mail filers what is real and what is not. Click on the sample below which illustrates how to reclassify email in Thunderbird.