Let's Encrypt ACME TLS-SNI-01 end of life

I received this email today and wanted to know what I should do, server wise.

Hello,

Action is required to prevent your Let’s Encrypt certificate renewals from breaking.

Your Let’s Encrypt client used ACME TLS-SNI-01 domain validation to issue a certificate in the past 60 days.

TLS-SNI-01 validation is reaching end-of-life and will stop working on February 13th, 2019.

You need to update your ACME client to use an alternative validation method (HTTP-01, DNS-01 or TLS-ALPN-01) before this date or your certificate renewals will break and existing certificates will start to expire.

If you need help updating your ACME client, please open a new topic in the Help category of the Let’s Encrypt community forum:

https://community.letsencrypt.org/c/help

Please answer all of the questions in the topic template so we can help you.

For more information about the TLS-SNI-01 end-of-life please see our API announcement:

https://community.letsencrypt.org/t/february-13-2019-end-of-life-for-all-tls-sni-01-validation-support/74209

Thank you, Let’s Encrypt Staff