For persistent problems, add a filter to override the spam filter. Also, log in online to see if your email provider is the one forcing the spam setting.

Hi David, I am not well-versed on how to do things on Thunderbird, even though I have been using it since Outlook Express went away. So, how do I go about adding the filter, and does that just apply to the one email address or all email addresses. I did find a list of email addresses that were automatically marked as spam, his email was on that. When I removed his name from that list the problem seemed solved. It was for about 2 weeks. I stumbled on that list and can not find it for the life of me. Finally, when you say login online, who are you talking about? Sorry, I am so slow on this. It's been a pain. It might eventually force me away from Thunderbird. The address in question is, as far as I can tell perfectly legitimate, and has been in use for several years. Thank you so much for your time and consideration. Michael Tad Parks+

Wow. Outlook Express. That comment brings back many good memories. :) Okay, regarding online, I was suggesting that you log onto the website that maintains your email address. For example, if you have a Gmail email address, you could access the account by going to gmail.com with your browser. The suggestion to try online is to see if your email provider is setting that email as spam. If so, the message will be spam before Thunderbird receives it.

On filters, you can do that at tools>message filters. Set the filter to search for FROM contains and specify the email address there. For action, I suggest marking it as not spam. In upper left part of that screen is the place to set whether to run the filter before or after the spam check. I would try setting to AFTER the spam check.