Currently Being ModeratedAug 27, 2013 4:45 PM (in response to Yarramalong)
I have had all of mine vanish completely. Not just as to being with accounts, not listed in siguatures at all; just gone. They are all still in the Users/[name]/Library/Mail/V2/MailData/Signatures folder, but no matter what I do, Mail won't see them. They seemed to vanish around the same time as my rules, which I noticed right after a power outage. Maybe Mail didn't close properly, but heaven knows I've crashed before and not had this happen!
I managed to tinker until I got the rules back; it seemed to be a case of files in the wrong places, though how they got moved is a mystery!, But I haven't been able to do the same with the sigs. I've tried removing all the plist files from the Signatures folder, all at once and individually, but no luck.
The other things I tried (with regard to both rules & sigs) are here: https://discussions.apple.com/thread/5265759
OK, I was able to restore from a backup. It seems that somehow (no clue how/why) all the ".mailsignature" files went A.W.O.L., leaving only the ".webarchive" files for each sig. As I told the other thread, it's fixed in the sense that it works, even if not solved in that I know what went wrong, and I really wish I did.....