Any similarities in the subjects? Depending on the email client, you might could filter out based on that.

Could try an email filtering program, my dad uses popfile I believe its called. It is a go-between your email server and your email(it downloads email from the server, then your email client downloads from popfile). Then you can go into PoPFile, and mark which messages were spam or personal.

After a few dozen-few hundred messages, it starts learning based on words contained in the email, and in the subject.. which emails are bad, and which are good. You can even put magnets on specific words, so they never can be classified as spam. Then it puts a [spam] or [personal] in front of the email and they arrive in your email like that. Then you can just make a simple message rule so that "[spam]" is forwarded to the trash can, or junk email folder. Then you'd just have to check it the first few times(or if paranoid and don't want to lose anything... all the time) by skimming the junk mail folder, then emptying it.