Let's Encrypt certificate expiration notice for domain

[mattia]

Just received an email from Let’s Encrypt that just my domain certificate will expire in 20 days (on 18 May).

this is the most recent website that I did with trellis, I never received this email with other old trellis projects.

So I am wondering if it is something new and I should take action in order to avoid problems?

as far as I know, trellis takes care of the renewal automatically and I don’t need to care about this, but again, this is the first time that I received this email, so I am not sure if this is a new thing or I made some sort of errors with the SSL?

when I check details of the SSL on the browser I can see that it is valid and it is going to expire on 8 june

so I am more confused because in the email says 20 days (on 18 May) but when I check the SSL on the browser I can see 8 june.

do I need to do something special or I can ignore this email because trellis will take care of the renewal?

what test can I do in order to see that everything works as expected and avoid surprises on 8 June (or on 18 May)?

many thanks

[strarsis]

Yes, I also get Let’s Encrypt certificate expiration notices from time to time.
These are sent before the certificate expires so the admin is reminded that the renewal mechanism should work as otherwise the cert will expire in the near future, disrupting the function of the site

For avoiding surprises it is always a good idea to use a HTTPS monitor (not just HTTP!) with certificate-check (some don’t check the certificate/HTTPS validity!). statping looked nice as a free and self-hosted solution but sadly isn’t currently maintained.
Sadly uptimerobot doesn’t offer free HTTPS/cert checks, only HTTP monitoring is free.