Hi, what’s MDaemon?
It sounds like you are new to using Let’s Encrypt to request your certificate. HTTP validation (the default) is usually the easiest method and is most often fully automatic. I’d need to read up on what MDaemon is and what instructions they normally provide for configuring certificates to provide more help, so please do link to what you already have.
Http Validation normally works by starting our own temporary http listener on port 80, responding to the domain validation request from Let’s Encrypt. Sometime this approach can’t be used if you have your own (non IIS) web server, so you need to point it to the website root path so it can write the files as text.
If you instead need to use DNS validation, this involves automatically setting a TXT record in your DNS and if you are using EasyDNS then you will be going via our Posh-ACME provider. For the instructions (EasyDNS - Posh-ACME) it sounds like you need to email the easy dns support team to get your API token set up. This token and key will be created in your Easy DNS account. There are literally thousands of possible DNS providers, so we only support some. The easiest to use are things like Cloudflare.
I understand your frustration as there is quite a lot to learn and potential for confusion, however we are not a certificate authority and we don’t make any of these rules, we just provide software to help make it happen.