I have a 2006 iMac with a bad screen that I have connected to an external monitor. I recently purchased a Mac Mini and would now like to transfer all my files to the new Mac Mini, but learned that my iMac is too old to be used with migration assistant, so I've been transferring my photos and music files to CD-R discs and have spent 48 hours going through 7000 email messages in Apple Mail that I've narrowed down to 3000 that I want to keep. So basically what's left is 3000 emails in Apple Mail and a lot of (about 800) .pdf and .txt files scattered throughout different folders that I would like to keep. How/what is the easiest way to put these documents and old emails on a USB flash drive all at once? Secondly, once I have deleted all files from my old iMac, what's the simplest way to pepare it for donation to where the next person couldn't uncover anything or the computer would have no trace that I owned it? Going through 8 years worth of old emails and files is time consuming. I hope transferring them is less so.