Short answer: disable TB's Junk Controls, and try using the spam controls applied by the mail provider. The 'spam' may be sent to a Spam or Bulk Mail folder, depending on the provider, and if your account is set up as IMAP, that folder can be subscribed in TB to monitor its contents. You may have to whitelist or unblock certain senders on the webmail site, possibly by adding them to webmail contacts, but this method might be far more successful than the Junk Controls, especially if the account is with one of the major providers.

Is this a POP account or an IMAP account?

In the Account Settings > 'Junk Settings' Have you selected the checkbox to 'Trust junk mail headers set by' eg: spamassassin ? If the server spam filter set as Spam, then Thunderbird will put that email in Junk if the above checkbox is selected.

If this is an IMAP account, it is possible that the server is marking it as Spam and putting it into the 'Junk Mail' folder which you then see because the folder synchronises with server.

It is an IMAP account. I have had the checkbox as noted in your reply unchecked but it didn't change anything.

sfhowes (Top 10 Contributor) - It is an IMAP account. I did see the whitelist suggestion on Help and had tried to find a way to add them to a Whitelist but I'm sorry that I couldn't figure out how to do that. I did add both email addressed into my Personal Address List several days ago and it changed nothing.

I meant that 'whitelist', or whatever term is used by the provider (unblock, allow etc.), be applied on the provider's webmail site, so that spam filtering is applied before mail is downloaded to TB. This may seem a bit clumsy, but simply marking a message as 'not Junk' in TB doesn't affect the classification at the mail server end. In the same way, you may have to add the senders to the webmail address book.

Ok thank you. I appreciate your replies. I'll have to get help from the provider at some point. Their chat is not helping me get anywhere.