If your account is IMAP, Mail reflects the status of your account on the host computer's IMAP server where the folders messages are physically stored and your next logical step would be to contact the email provider…
Contact with the email provider has been made and I await, with trepidation, the results of their ability to recover or not.
meanwhile, this morning I booted from my Super Duper backup, with ethernet disconnected to avoid the ISP’s system changing the Mail files on that drive. When I open Mail on the SD backup, all of my folders are there and I am able to read them, so it appears that “something†allowed them to be stored on my computer.
So, in case the ISP is unable to find my mail, I assume that that its presence on the SD backup will allow me to “get them back†to my computer, albeit only to the date of the last backup. I’ll give the ISP a few days to get my files back but, in case they don’t……
Questions:
1. How would I restore the files from the SD backup to my computer?
2. I assume that such a restoration will eliminate all mail since the date of the last backup. If so, how do I protect the newer mail?
3. Can all of this be done without destroying the mail on the SD drive?
4. If Super Duper has the files I assume Time Machine does too, except perhaps a bit nearer to the disappearance. If so am I better to try with Time Machine?
5. If Time Machine is best, and I am to recover to the User Library, there is the matter of the User Library being invisible. If I make the Library visible first (Shift/Command/Period), will it be visible to a Time Machine search?