@mxroute I tested your domains and found that two of them had “mail” subdomains but not “webmail” subdomains in their DNS (the other two had neither). Please make sure that you follow this guide, or if you do not that you adjust all parameters relatively:
To confirm that LetsEncrypt is working, I created an SSL certificate for the “mail” subdomain on one of your domains (b------f-------.com) and it worked fine. But note as stated in the guide, this is only for POP/IMAP/SMTP and not webmail. If intentionally not using the webmail part, you’ll need to also uncheck that hostname when following the steps to finalize the certificate creation.
It may give you trouble now trying to fix the domain that I did that on, if you decide to add the webmail subdomain later. I do not know a fix for that if it does (last time I had to delete and re-create the entire account). I highly recommend following the guide to the letter for that reason, as I may have broken that chance for you by having to test it outside of the intended workflow.