Should be Opened Mail - what it looks like when it isn't

Sometimes when I open mail, it doesn't open... but the mail icon looks like this! XD It happens a lot but I felt like taking a picture. Seems like not many people have had this happen to them but I'm sure some have! :D P.S. Please become a member of my blog if you can (if you haven't already) and/or comment! :) Thanks a ton!