Take a look in ~/.local/share/evolution/mail/If everything there is OK, that will probably relax you. You can backup all Evolution's informations data by copying ~/.local/share/evolution/ somewhere else.
Evolution's configuration is stored in ~/.config/evolution/ (~/.config/evolution/mail for the mails). You *might* want to erase that for a fresh start. Although, if I were you, I would wait for the advice of more users: maybe someone had the exact same problem and solve it.
