I am running a mail server on Windows platform. I rent a vps on Godaddy. There is no web server on this server. Currently, I install the signed cert manually. I want to get a cert from Let's Encrypt but fail.
I don't see that you need any help getting certs. Can you explain more about your question? Also, had you posted in the Help topic you would have been asked the questions below.
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Please fill out the fields below so we can help you better. Note: you must provide your domain name to get help. Domain names for issued certificates are all made public in Certificate Transparency logs (e.g. crt.sh | example.com), so withholding your domain name here does not increase secrecy, but only makes it harder for us to provide help.
I ran this command:
It produced this output:
My web server is (include version):
The operating system my web server runs on is (include version):
My hosting provider, if applicable, is:
I can login to a root shell on my machine (yes or no, or I don't know):
I'm using a control panel to manage my site (no, or provide the name and version of the control panel):
The version of my client is (e.g. output of certbot --version):
Can you show the answers you gave? Because you can get certs for those mail domains the same way. That is, with a webserver that replies on port 80 (http) for that name. Even if you setup a "fake" webserver just for those names.
If you don't have or want a webserver for your mail domains, you can maybe use certbot standalone or even DNS challenge.
When you said "I answered all the questions, but fail" I don't know what you tried.
C:\Certbot>certbot certonly
Saving debug log to C:\Certbot\log\letsencrypt.log
How would you like to authenticate with the ACME CA?
1: Spin up a temporary webserver (standalone)
2: Place files in webroot directory (webroot)
Select the appropriate number [1-2] then [enter] (press 'c' to cancel): 2
Please enter the domain name(s) you would like on your certificate (comma and/or
space separated) (Enter 'c' to cancel): umx.ccpl.cloud
Requesting a certificate for umx.ccpl.cloud
Input the webroot for umx.ccpl.cloud: (Enter 'c' to cancel): c:\certbot
Hint: The Certificate Authority failed to download the temporary challenge files created by Certbot. Ensure that the listed domains serve their content from the provided --webroot-path/-w and that files created there can be downloaded from the internet.
Some challenges have failed.
Ask for help or search for solutions at https://community.letsencrypt.org. See the logfile C:\Certbot\log\letsencrypt.log or re-run Certbot with -v for more details.
Option 2, the "webroot" expects a webserver, but you mentioned you're not running a webserver on that host. Setting the webroot to a fairly random directory won't help.
You probably want to choose option 1, the "standalone" plugin. This plugin will spin up a temporary webserver on port 80 to handle the challenge.
That said, why is there an Apache listening on that host whereas you said there isn't a webserver running? I'm puzzled now..
You can't use option #1 [Spin up a temporary webserver (standalone)], if you already have Apache listening on port 80.
[but we are not yet sure if that is the case]