cyrus imap running with id = cyrus, and that id needs to read certificate

/usr/pkg/etc/letsencrypt/archive/

at least we need this, without this, you'll get following at /var/log/messages

Dec  4 20:21:27 imap4 imaps[20616]: TLS server engine: cannot load CA data
Dec  4 20:21:27 imap4 imaps[20616]: unable to get certificate from '/usr/pkg/etc/letsencrypt/live/ki.nu/fullchain.pem'
Dec  4 20:21:27 imap4 imaps[20616]: TLS server engine: cannot load cert/key data
Dec  4 20:21:27 imap4 imaps[20616]: error initializing TLS
Dec  4 20:21:27 imap4 imaps[20616]: Fatal error: tls_init() failed

1. 更新前の期限を調べておく (993, 587) 以前の日記

           Validity
               Not Before: Sep  5 22:36:44 2021 GMT
               Not After : Dec  4 22:36:43 2021 GMT
   

2. DNS の変更の準備をする
3. certbot を起動する

   X3@root 20:00:32/211204(/home/makoto)% certbot-3.8 certonly \
        --manual \
        --server https://acme-v02.api.letsencrypt.org/directory \
        --preferred-challenges dns \
        -d '*.example.com' \
        -d example.com \
        -m makoto@example.com \
        --agree-tos \
        --manual-public-ip-logging-ok
   

4. DNS の変更をした上で、本当に変っているか調べて

   dig  +noall +ans txt   _acme-challenge.example.com @8.8.8.8
   

   (https://qiita.com/szk3/items/3eb2137de32e25e47c66)
5. certbot に Enter を入力
6. 出来た証明書を server に copy
7. cat full+priv > full+priv
8. chmod x 2 (top directory と archive)
9. cyrus を{再起動)
10. 期限を調べる (993)
11. sendmail を再起動
12. 期限を調べる (587 -starttls smtp)

        Validity
            Not Before: Dec  4 10:02:52 2021 GMT
            Not After : Mar  4 10:02:51 2022 GMT