> so you may not miss much unless someone’s DNS resolver had a poor caching strategy
Microsoft Exchange used to (hope it doesn't still?) cache MX records until the service restarted. :( There's a long tail of braindead software in the DNS space
MTAs should queue undeliverable addresses for more than four days, so you may not miss much unless someone’s DNS resolver had a poor caching strategy or Shadowserver used a long TTL. At least the name still resolved (else the mail would have been dropped immediately). Some mass mail senders may go to less effort to get their messages through.
The fact that people responded so “quickly” helped here. I put “quickly” in quotes as it was quick enough to possibly cause no message to be lost — I’m sure it was super stressful and didn’t feel quick at all!
Glad you got your name back.