Installing Mavericks was the single worst thing I've ever done with my Mac. Installed it about 8 months ago and have had nothing but problems and a slow running computer. Now Mail seems to have gone screwy. Won't send any e-mails at all. 3 different mail account. Sometimes it sends a mail, and other times it won't, for no apparent reason. I've bought a large external drive to back up and save everything, so I can get rid of Mavericks. Can anyone let me know the actual procedure for doing this? Do I just drag the entire contents of my HD into the new drive? I have a disc of OS 10.6, so will have to revert to that until I can upgrade further.