I have used Thunderbird for many years, and use it with two email accounts without any issues. After the latest update today (first to 102.4.1 then 102.4.2) I can still send/receive emails correctly, but sent emails are no longer saved anywhere (locally or on the mail server). After checking the forum I tried to subscribe and refresh for all folders on the account, but it makes no difference. Finally (just this minute) I have found the solution! (Maybe helpful for someone else?) - I had to change the account settings in "Copies & Folders" for "When sending message, automatically:" it seems the latest update screwed up those settings. That's something that should be highlighted to the user or smoothed out in the auto update(102.4.3?), as a result I have completely lost all records of some sent emails from this morning. I will have to email the recipients and ask them to send me a copy for my records!! Not very convenient! This is the first time I have had an issue like this with Thunderbird in over 10 years of use!