Need Help With Email? Ask Your Email Questions Online
I have done much research on this and do not see a way. There seems to be a way on a Blackberry. I checked thunderbird support and there is no way to hide one from out of site or lock it. Sorry
I did find this but I dont think it goes as far as you want.
Hide list of accounts in left window while in unified folders mode
I wish I had a better answer for you. I have seen some people do it by just using a web version to check email when needed. Not convenient but serves the purpose. I will forward your concern to customer service about the second charge.