Mail 5 bugs! Please help!

Hey guys, so my mail app on my new macbook air seems bugged. Whenever I type in the search box starting with the letters "s" or "h" it closes and says error. I thought this was a bug with the mail app but then tried on my wifes computer the same letters and it worked fine! I think there might be a couple other letters it bugs on too.

Anybody know why this is or how i can fix it?! Do i have to uninstall mail and reinstall?! how would i do that.....please any help would be much appreciated!

Thank you!!!

 

So, I have a very odd update.

Now the "S" key seems to work! It lags after I type it in but doesn't shut down the program. But the "H" key still does?! What is going on.....this is soooo ODD!
I think i need to reinstall mail 5 but not sure how.

I really don't get how it just fixed the "S' key on its on but the "H" still not working.

Im lost for words and what to do. Any input would be great!

Thanks!