I've discovered you cannot just grab that old pic from your archive of attachments and re attachment. That is because the list of valid file name extensions (bmp doc gif jpe jpeg jpg pdf png psd txt zip) for attachments doesn't include the extension that comes up when you go to your Control panel and select attachments and then click on one of them, as I did with this..........................
That is my feeling, wasting space. If you use the manage attachments and plug in the URL of an existing attachment, which displays just fine in another browser window, and try to upload from a URL, it tells you it is an invalid file. Apparently the BBS changes it in some way and cannot reuse it. I end up re-uploading the file, which is time consuming to find it on my computer (if I can at all) and also not thrifty with the space.