Mail keeps deleting all my signatures I'm in the process of reinstalling everything after a clean install (Mavericks) on an iMac. Mail seems to be working okay but none of my signatures are showing up in preferences. I have copied back the folder ~/Library/Mail from backup, which in turn contains V2/MailData/Signatures. In addition to a couple of sig-related preference files, that folder holds a whole load of cryptically-named files, each of which is stored twice -- once with a .mailsignature suffix and once with a .webarchive suffix. 

When I launch Mail it seems to delete the .mailsignature files from the folder leaving only the .webarchive files, and as a result I am left with no signatures. Every time I copy the contents of the Signatures folder back from the backup the same thing happens; Mail deletes the .mailsignature files. I can also see that the AllSignatures.plist file gets re-written to empty (the one I'm copying in from backup is not empty). I don't know whether that is a product of the files being deleted, or vice versa.

Extra info:

I have iCloud enabled for Mail and my other Macbook Air (also with iCloud enabled for Mail) is showing my signature collection just fine (though I'm a bit worried that iCloud is going to tell the laptop to delete its signatures as well). Certainly iCloud is not pulling signatures over from the laptop, which makes me wonder what else is not being kept in sync. [I just created a Smart Mailbox in Mail on the laptop to see if it appeared on the iMac. It did not. So presumably iCloud is not correctly syncing on Mail, although Safari bookmarks are updating between the two macs]. That doesn't necessarily explain why the Signatures keep being deleted though.

Can anyone help?
I have a problem with my signatures too, and perhaps, this may help.

My problem was, that on my Mac, my Apple ID (my mail address) was used not only for login but also as mail address and alias for the iCloud mail account. And I can't change it.

After deactivating the iCloud mail account, I was able to use the signatures of my normal mail account again.