How to vertify a certificate for postfix and courier

Hello anyone

I’m using the letsencrypt script for my plesk webserver works fine, but i want to create a cert for my mailserver (hosted on the same machine like plesk webserver). But my idea is to use the manual command. But i cant vertify the subdomain because the randome generated file is not accessible.

Here is my what I have done:

./letsencrypt-auto certonly -a manual -d
–server https://***** --agree-dev-preview

Message Box: “Are you Ok with your being logged?” -> Yes


Unable to reach x


  • The following ‘connection’ errors were reported by the server:

    Error: The server could not connect to the client for DV

    To fix these errors, please make sure that your domain name was
    entered correctly and the DNS A record(s) for that domain
    contain(s) the right IP address. Additionally, please check that
    your computer has a publicly routable IP address and that no
    firewalls are preventing the server from communicating with the

Any idea how to vertify my mail2. Subdomain, its a A-Record.

Best Regards,


If I remember correctly, manual verification requires that nothing is running on port 443. Have you considered creating a webhost for your mail2 subdomain, letting LE verify it like it were, and then use that same certificate for your mailserver?