I have 4 emails accounts, (msn, comcast, google and gmail). I have no idea what I did but now all I can see and/or bring up is "msn." the side column that housed all the others email accounts and their subsets (inbox, sent, trash etc) is gone. I went into the Mozilla details and all emails are there, correct and in the page listing with details (I did not change anything here).

I cannot restore to original view??