Hello Doug Post,
Windows Live Mail 2012 has been end-of-support for a long time, and on top of that Microsoft retired the old DeltaSync protocol it used for Outlook.com/Hotmail accounts a while back. So if your email is an Outlook.com or Hotmail address, WLM hasn't really been able to sync new mail for some time, and an ISP outage just brings that to the surface.
Whether your mail is actually "lost" depends on what kind of account you have set up in WLM:
- If it's an IMAP or Outlook.com account, your mail lives on the server, not on your PC. Once you re-add the account in a modern client, everything reappears from the server. Nothing is gone.
- If it's a POP account, the mail was downloaded and stored only on your PC. WLM keeps it as
.emlfiles in%LocalAppData%\Microsoft\Windows Live Mail\— you can paste that path into File Explorer to confirm it's still there.
Going forward, the cleanest path is to move to the new Outlook (free, included with Windows) or Thunderbird if you'd prefer a non-Microsoft option. Both can import your existing WLM .eml files, so you don't lose anything in the move.
If you can share what type of account you have (POP, IMAP, or an Outlook.com/Hotmail address) and whether the old mail is still showing in WLM offline, I can point you to the exact next step.