Hopefully, I can explain this to where it makes sense. I have been having a long term issue with Thunderbird replacing received emails with existing emails that I have already received. Example: I get an email from tom@email.com titled "Hello." I get an email after that from joy@usa.com titled "Need Your Help." Thunderbird will replace the email from joy@usa.com with the email from tom@email.com and then I have two emails from tom@email.com in my inbox and the one from joy@usa.com is gone. If I sign into my webmail client, both the emails from tom@email.com and joy@usa.com are there with no duplicates like in Thunderbird. So, this indicates to me this is a Thunderbird issue. It happens randomly too. Sometimes I can go days without this happening and then suddenly it happens multiple times a day over several days. Is anyone else having this issue and is there a solution?