To fix these errors, please make sure that your domain name was entered correctly and the DNS A/AAAA record(s) for that domain contain(s) the right IP address

[sokha]

when I try to obtain a TLS certificate with an Nginx web server I get this error. note in my domain I try to set host record like below
Type of host records (Type A) (Host @) (value my public IP) and one more in a record I try (A) record (host mail) and (value my public IP). in MAIL SETTINGS I set MX record Type Host @ and value mail.mydomain.com
IMPORTANT NOTES:

• The following errors were reported by the server:

  Domain: mail.krongsamrith.com
  Type: unauthorized
  Detail: Invalid response from
  http://mail.krongsamrith.com/.well-known/acme-challenge/fwLzw5-PzLovi04G8wIH85UHPb3odtVzPrbsyrGFSEQ
  [119.15.81......]: "\r\n404 Not
  Found\r\n\r\n

  404 Not
  Found

  \r\n

  ---

  nginx/1.18.0 (Ub"

  To fix these errors, please make sure that your domain name was
  entered correctly and the DNS A/AAAA record(s) for that domain
  contain(s) the right IP address.

[JuergenAuer]

Hi @sokha

what says

nginx -T

[rg305]

Then there must be something about your nginx config that has confused certbot.
We could review the nginx config, show: nginx -T
Or we could use --webroot authentication instead.