I'm no stranger to my iMac and my plan to resolve is to reinstall mail.app from disc, but I'm curious if anyone has any info on how this could have happened to prevent it from happening again. My iMac has been flawless for years, nothing has changed with it system wise since it's normal updates. Today I tried to click mail from the dock and it showed the darkened question mark over it to alert me the app was not found on the shortcut. I'm baffled as to how I can walk away from the iMac and come back to this if I didn't do anything. I verified and fixed disk permissions to no avail. I cannot find mail.app in the applications folder. I'm concerned there may be an issue with security since it has done this without my interaction. Does anyone have any possible explanations? I dual boot 10.6 and 10.7 and this issue is with 10.6, which I simply prefer.