Hello, I sent the message below last evening and someone named "Ed" replied. Thank you Ed. When I tried to "reply" to his/your question/email, I immediately got a bounced back email as "no-reply@support.mozilla.org" could not be found. Also, in my original question I said that I'm not "computer illiterate"; apparently I am as I don't know how to reply to his question. Please include info on how I can respond. So, I'll start all over by sending my original question: Hello, Attached are the messages I have been receiving ever since 6 October 2025. I've tried to read about fixing these myself, to no avail. (I mean, I can Read; I just can't fix this.) I've tried to Compact ALL folders individually. But that seemed to do nothing. (Before 6 October, the Thunderbird window would at least "flicker" a little after compact.) Trash is empty. Tried disabling McAfee AntiVirus & Firewall. And, no, this isn't happening because I'm using McAfee; I've been using McAfee since Windows XP and Thunderbird since before it "broke away" from Mozilla. They have, until 6 October, played nice together. I really like Thunderbird so I do not want to find another email client/program/what-have-you. There are LOTS of saved emails that I cannot move/copy to "save space", so...Help? Please? Thanking you in advance, tonyg P.S.-I am not computer illiterate. But, slow, easy to follow, non-BIOS changing, step by step directions would be preferred.