Someone viewing my email


New Email
I would really appreciate some help on this. I have been noticing on my email acct when I log on,some messages are 'grayed out' (as if opened-not by me) ..and some are bold black,(not opened-usually advertisements). My daughter also works for me...same thing, except one day as she logged on,her appx 145 emails starting disappearing one by one. These email accts are through Homestead.We suspect my husbands partner has done something..but we do not know what. He seems to know everything she or I do concerning business...please help & advise on what is possibly going on. Thank you