About a month ago I received the same thing, so it seems I’ll be getting this supposedly useless email every month. I’m assuming there might be a discrepancy between my server and the letsencrypt servers.
Does anyone have any suggestions or advice on where to turn or what to do?
For what it’s worth, the “certbot certificates” command also displays your certificates and their expiration dates (but not the notBefore date).
What’s your domain? Which certificate is it? Usually this happens when you have multiple, similar certificates, after adding or removing a subdomain or something. Let’s Encrypt sees that the old certificate you no longer use is expiring and sends you an email.
If Certbot’s operating with a typical configuration, and nothing goes wrong, you’ll never get expiration warning emails (except for false alarms from certificates you’ve deleted).