I keep special ones, but in general I delete them from my inbox but not from my sentbox; as I usually reply with a quote to the original message, nothing actually gets lost. Other than that, it depends who each message is from.
That's a good idea, and something I'll probably do, but wouldn't it be better to save different messages from both boxes, depending on whether you sent the last message or not? I also usually reply with quotes, so I think with the majority I can just save the last PM from whole conversations since it will have all the other PMs quoted within it.
Also, I've tried the download message option before, but I didn't like how it came out, so that's not going to be a real solution for me.
This all has made me want to start deleting some of my PMs, but I'd really like to get to 100% full, so I can't do it quite yet.:biggrin1: