Category Archives: Linux Administration

Webmin Postfix: How to solve “Host or domain name not found”

Error Host or domain name not found. Name service error for name=”XYZ” type=AAAA: Host not found Host or domain name not found. Name service error for name=”XYZ” type=A: Host not found Here XYZ is the host name of the droplet and NOT the domain name. For example if my server’s Fully Qualified Domain Name (FQDN) […]


Webmin Let’s Encrypt: XYZ is not a valid e-mail address

Error acme.messages.Error: urn:ietf:params:acme:error:invalidEmail :: The provided email for a registration was invalid :: Error creating new account :: “XYZ” is not a valid e-mail address Root Cause In my case, I created Virtual Server without the email feature enabled. Hence when Webmin tried to generate Let’s Encrypt SSL Certificate, it used the default email address. […]


Webmin Let’s Encrypt Throws “Failed to Establish a New Connection”

Error requests.exceptions.ConnectionError: HTTPSConnectionPool(host=’acme-v02.api.letsencrypt.org’, port=443): Max retries exceeded with url: /directory (Caused by NewConnectionError(‘<urllib3.connection.VerifiedHTTPSConnection object at 0x7f94951b7860>: Failed to establish a new connection: [Errno -3] Temporary failure in name resolution’,)) Root Cause When Webmin tries to send request to Let’s Encrypt, Let’s Encrypt is trying to get the response from the Website index page. If Let’s […]



Webmin: How to change the size of Swap?

Even after searching on internet, I could not find a way to change the Swap size. Various online tutorials only showed us how to create swap space but did not explicitly address how to change the size of swap space using Webmin. Of course, this tutorial does not use Webmin but instead it uses commands […]