今天通过 acme.sh 给新域名申请 SSL 证书，遇到报错：

[Mon Jul 12 15:53:31 CST 2021] Using CA: https://acme.zerossl.com/v2/DV90
[Mon Jul 12 15:53:31 CST 2021] No EAB credentials found for ZeroSSL, let's get one
[Mon Jul 12 15:53:31 CST 2021] acme.sh is using ZeroSSL as default CA now.
[Mon Jul 12 15:53:31 CST 2021] Please update your account with an email address first.
[Mon Jul 12 15:53:31 CST 2021] acme.sh --register-account -m my@example.com
[Mon Jul 12 15:53:31 CST 2021] See: https://github.com/acmesh-official/acme.sh/wiki/ZeroSSL.com-CA
[Mon Jul 12 15:53:31 CST 2021] Please add '--debug' or '--log' to check more details.
[Mon Jul 12 15:53:31 CST 2021] See: https://github.com/acmesh-official/acme.sh/wiki/How-to-debug-acme.sh
Error: Create Let's Encrypt SSL Certificate failed!

有人说需要在 ~/.acme.sh/account.conf 中添加：

ACCOUNT_EMAIL='xxx@xxx.com'

但是需要邮箱地址终究是麻烦，希望切换回 Let's Encrypt，可以这样：

# .acme.sh/acme.sh --set-default-ca --server letsencrypt
[Mon Jul 12 15:54:19 CST 2021] Changed default CA to: https://acme-v02.api.letsencrypt.org/directory