|Valid from| Tue, 19 Dec 2017 11:31:54 UTC|
|Valid until| Mon, 19 Mar 2018 11:31:54 UTC (expires in 2 months and 2 days)|
However, I received an email today, warning me that the certificate is about to expire today…
Your certificate (or certificates) for the names listed below will expire in
0 days (on 18 Jan 18 06:12 +0000). Please make sure to renew
your certificate before then, or visitors to your website will encounter errors.
If the most recent certificate contains a slightly different set of names to a previous certificate, then you will still receive emails about the previous certificate expiring (even though you don’t really care about the previous certificate).
That is the most likely explanation.
However make sure to check that the certificate that the SSL Labs test sees is indeed your Let’s Encrypt certificate - it can be misleading if you are e.g. using the Cloudflare CDN service.
If you care to reveal what your actual domain name is, then we would be able to provide you with an exact explanation.
But back in October, in addition to a certificate like the above, you also issued another certificate (https://crt.sh/?id=235756414), that has only one name. Maybe while you were figuring out how to use Let’s Encrypt:
scti.gr
The email you received will have been about this single-name certificate. If you are not using it, then you can safely ignore the email, and it won’t come back to bother you .