Hey, I just bought a 5k Retina Imac. So far so good and the performance is plenty for me. I don't do much beside the normal webmaster stuff. Google chrome, Skype, MacMail, Word, iTunes are the apps that are always open. I noticed a lag when getting my emails or in general when changing settings in MacMail. Is this a specific MacMail issue or do I need more RAM to keep up with the workload? Was thinking about buying 4x8gb sticks since the prices are really low these days, but if it doesn't fix the Mail issue, I am pissing money away basically. Any thoughts ?