how do I get my 3 email accounts to use the same inbox

Click view>folders>unified folders and thunderbird will create a virtual inbox folder

Hi, thanks for your reply, but it didn't work. I think it's because they are IMAP configured

It has nothing to do with IMAP. Please give explicit details on whatever you are doing. What do you mean, in details, on what I suggested? That was just a menu selection. Tell me exactly what steps you took. thanks.