Before you blame Thunderbird are you sure your provider is not filtering them into other folders on the server? When you log into your account at the providers webmail page do you find the missing messages? Thunderbird downloads messages from your inbox on the server but they have to get there first.

Feel free to use any email client that you want.

Not "Blaming" Thunderbird. Just trying to look for solutions as we have checked on both the inbound mail provider and all of our junk mail and security features and there is nothing that shows we should not be receiving emails.

Is it possible that there is an issue with the file size of the emails we are storing in our Thunderbird folders? It's only been a little over a year that I switched to Thunderbird. And I never had this issue until just about 30 days ago.

We switched to Thunderbird from Outlook Express because we had issues with outlook when the mail file became too big.

How about answering the question - When you log into your account at the providers web mail page do you find the missing messages?

There is no webmail. It is the mail server hosted by our ecommerce provider bigcommerce. They do not have web mail access. And, they do not have anything on their end that would be blocking or moving emails to any folders.

Then ask them where your mail is going. Thunderbird downloads what is on the providers server. It cannot download messages that are not on the server. I have yet to see a provider that does not have web access to your mail. Maybe you need a new provider instead of a new client.

Maybe there's a filter set up? Go to Tools > Message Filters to find out.

Just looking for someone that is having the same issues. Sorry to bother you. Thought this forum was for support. But, just realized much differently.

Sorry if you're having a bad experience here. :( If you find the solution, feel free to post back here, so anyone with the same issue will see the solution as well.