Thanks for the tip. I'm not quite savvy enough to follow the directions post #30 gave, but I'm gradually beginning to get all of those recovered files delated and create space. Once there is a bit of space, it becomes progressively easier to do, it seems, though it is quite time-consuming. Just for the sake of others if they run into a similar problem, the pictures I sent out were in 4 separate emails with reduced size, with each being only around 500 or 600 kb. This was done about a month ago, and so they've just been sitting there, slowing down the computer since, and only reaching a crisis just recently. Only the first of the emails got "recovered" (and that was 10449 times!) and each of those appears to have somehow reverted to the original pictures in iPhoto, so that each email was listed at 41.4 mb! Those numbers don't quite add up, of course, as that would be over 400 gb, which I think is much more than the capacity of the computer, though I'm not sure how much capacity there actually is. But whatever, it's obviously the reason my disc was essentially full. Anyway, I apparently just have to delete blocks of them at a time, and have gotten rid of about 10% in a couple of hours of computer time. It's my office computer, and so by next week, I hope to be back to normal.
