Hello Fellow Thunderbirds, I have been running Thunderbird on my Mac for over a decade now, and recently upgraded from Thunderbird v91 to v102.4.1 I run 4 email accounts on Thunderbird. Three are standard IMAP, and one is Gmail. Amongst the problems I have encountered after the upgrade is this. Of the four accounts, when I try and reply to an email in the inbox of my email account hosted by Fasthosts, I hit reply and the window pops up as you would expect, with the email address(es) of the person(s) who originally wrote the email to me in the "To" section, and anyone copied in to the original mail in the Cc section, again as you would expect. Also, as you would expect from my settings set up, the previous email or emails from the thread of messages so far appears in the body of the message, above which I can then type my message. So far, so good. However, when I then try and do exactly the same thing in any of the subfolders of this one account, although it displays the original email perfectly with all the addresses and body of the email visible in the subfolder via either the preview pane, or by double clicking on it and it appearing as a separate window, when I hit reply all that appears in the reply window is the subject header with the usual "Re:" in front of it. No emails in the "To" or "Cc" box of the people in the original email, and nothing at all in the body of the reply email, not even my signature. Then, when I look to close this reply window by clicking on the red cross in the top left hand corner of the pane, rather than it just disappearing (as there is nothing yet to save), I get the following message: "Save Message. Save this message to your drafts folder (Drafts) and close the Write window? " with the options to either "Discard Changes", "Cancel" or "Save". If I choose save, it appears in "Drafts" but just as it was in the reply window, without email addresses or body text. For clarity, the other three email accounts don't do any of this. I can go into any of the subfolders in them and reply just fine with everything coming up as it should. I also run this account on Spark via my Android phone, and on Spark I can access the email in the subfolder, and reply to it with ease with everything where it should be. Which makes me think that there is some issue not with any IMAP connection in general, but between Fasthosts server and Thunderbird in particular? Or is it something else? In the folder Properties I have always had the Synchronisation option of "Select this folder for offline use" selected, and just to see if it would make a difference I clicked on the "Download Now" button (there aren't many emails in the particular folder I'm trying this with) and the progress bar along the bottom says "Loading messages" and is making incredibly slow progress. Also, I have a blue spinning disc on my cursor (not the multicoloured "Beachball of death" usually associated with hanging and CPU overload) but can move around every part of Thunderbird as normal. Any help to try and crack this one would be hugely appreciated as it's making life very difficult.