HELP my screen is blue

So I lost my email sometime ago and put a post up last night - some helpful people gave me a link to reinstall the version I am running. Done that restarted and had 2100 emails downloading on my computer. Whoo hooo was so happy till it got to about 1900 emails then my Mac just froze. Turned it off then when I turn it on it looks as though its gonna start up and the apple icon appears then the screen just turns blue :(

My daughter looked on the net last night and it said to try open it in Safe mode..... Did that then restarted it but still the same blue screen.

Can someone please help me!!!