I have the Latest Thunderbird 115.10.2. I am running windows 11 pro 64-bit, 23H2 - OS build 22631.3447 I have run the latest downloads (KB5036980) My Mail server is run my Virgin Media. My email account Has 5 accounts, I seperately have an account with Fasthosts My wife has a gmail account and a company email for whom she works, So in total I have 8 seperate account from which I have set to download emails from. All my Thunderbird account ave been set up exatly the same with the exception of which servers they go to to down load emails. All accounts are required to automatically download every 4 mins, I have NOT ticked the - Leave meesages on server and both sub boxes - * so many days and - until i dele them all are unticked. The advanced box at the base of the Server Settings tab, is set to include this server (whiche ever of my accounts server it is) when downloading emails. My problem is that my web email for Virgin Media should receive all email for the 5 account I have with Virgin media. I have not set virgin media account to divert any emails. I was under the assumption that if Ive set up Thunderbird to download all my emails every 4 mins then nothing should be left on my web mail account, or so I thought. Due to my wife not receiving emails to her via 2 of her account, 1. Virgin media 2. her company email. So I wnet onto my web account with virgin media and to my horror i had 999+ in my inbox and had 500+ in the spam box. thinking this was the problem I set about deleting all the emails, 1st i emtied the spam folder in bulk delete. I then proceeded to delet one at a time just in cas i saw some that needed to be kept. The deleted email box hit 999+ minbox was still at 999+, cutting a long story shoert - I deleted of 8k emails, talk about sor index finger, and going cross eyed. My web mail inbox was now clear of emails, didnt last long, so by having my thunderbird open on one screen, I had the web maill account opebn on my 2nd screen. when email cam in some wer downloaded to thunderbird - some were not, even the ones that were down loaded stayed on the server and were not deleted. I checked every account in thyunderbird just to make sure i was not setting thing up correctly, I had. all the incomming mail has been for either me or my wife both accounts are with virgin media. Thunderbird downloaded only one of the emails to my inbox, it did not delet it from the webserver, no has the other 2 sent to me, the one for my wife, not her company email, is still stiing on the server and has not been downloaded. What is going on, its driving me crazy try to resolve a problem that I though I didn't have.