If I knew what you were using to read your email, I could tell you. Unfortunately you didn't say and without my crystal ball, nobody's going to be able to help you.
I have in the last day started receiving numerous (excess 30) spam mail stating "Spam Failure notice!" some appear to be eastern European/Russian. Always very careful of sites I use but could I have got it from a friends incoming email and if so is there anti virus I can use? Many thanks Tonybrode