Skip to content

Register now for our Web Enablement Ecosystem webinar!

  • Contact us: +34 944 58 06 58
  • Plesk Partner Program
  • Plesk Lifecycle Policy
  • Blog
  • Contact us
  • Plesk 360
  • Contact us: +34 944 58 06 58
  • Plesk Partner Program
  • Plesk Lifecycle Policy
  • Blog
  • Contact us
  • Plesk 360
  • Solutions
    By Role
    • Developers
    • Content Managers
    • Digital Agencies
    • IT Admins
    • Web Hosters
    • Hyperscalers
    • Developers
    • Content Managers
    • Digital Agencies
    • IT Admins
    • Web Hosters
    • Hyperscalers
    By Edition
    • Web Admin Edition
    • Web Pro Edition
    • Web Host Edition
    • Business & Collaboration
    • Plesk WP Edition
    • Web Admin Edition
    • Web Pro Edition
    • Web Host Edition
    • Business & Collaboration
    • Plesk WP Edition
    By Cloud
    • Amazon Web Services
    • Microsoft Azure
    • Alibaba Cloud
    • GCP Marketplace
    • Vultr
    • DigitalOcean
    • Linode
    • UpCloud
    • Amazon Web Services
    • Microsoft Azure
    • Alibaba Cloud
    • GCP Marketplace
    • Vultr
    • DigitalOcean
    • Linode
    • UpCloud
    Partner Program
    Exclusive discounts, benefits and exposure to take your business to the next level
    Become a partner
    • By Role
      • Developers
      • Content Managers
      • Digital Agencies
      • IT Admins
      • Web Hosters
      • Hyperscalers
    • By Edition
      • Web Admin Edition
      • Web Pro Edition
      • Web Host Edition
      • Business & Collaboration
      • WP Edition
    • By Cloud
      • Amazon Web Services
      • Microsoft Azure
      • Alibaba Cloud
      • GCP Marketplace
      • Vultr
      • DigitalOcean
      • Linode
      • UpCloud
    • Partner Program
      • Partner Program
  • Product
    Explore Features
    • Everyone
    • Admins & Web Hosters
    • Developers
    • Designers & Agencies
    • Plesk Features
    • Everyone
    • Admins & Web Hosters
    • Developers
    • Designers & Agencies
    • Plesk Features
    Key Topics
    • SocialBee
    • WP Toolkit
    • Sitejet Builder
    • SEO Toolkit
    • Joomla! Toolkit
    • Plesk Premium Email
    • Plesk Email Security
    • SocialBee
    • WP Toolkit
    • Sitejet Builder
    • SEO Toolkit
    • Joomla! Toolkit
    • Plesk Premium Email
    • Plesk Email Security
    Feature Packs
    • Business & Collaboration
    • WP Pack
    • Hosting Pack
    • Power Pack
    • Language Pack
    • Business & Collaboration
    • WP Pack
    • Hosting Pack
    • Power Pack
    • Language Pack
    Featured Extension
    SocialBee
    • Explore Features
      • Everyone
      • Admins & Web Hosters
      • Developers
      • Designers & Agencies
      • Plesk Features
    • Key Topics
      • SocialBee
      • WP Toolkit
      • Sitejet Builder for Plesk
      • SEO Toolkit
      • Plesk Premium Email
      • Plesk Email Security
    • Feature Packs
      • Business & Collaboration
      • WP Pack
      • Hosting Pack
      • Power Pack
      • Language Pack
    • Featured Extension
      • Extension
  • Pricing
  • Extensions
  • Help Center
  • More
    • Careers
    • Events
    • Plesk University
  • FREE TRIAL
  • Solutions
    • By Role
      • Developers
      • Content Managers
      • Digital Agencies
      • IT Admins
      • Web Hosters
      • Hyperscalers
    • By Edition
      • Web Admin Edition
      • Web Pro Edition
      • Web Host Edition
      • Business & Collaboration
      • WP Edition
    • By Cloud
      • Amazon Web Services
      • Microsoft Azure
      • Alibaba Cloud
      • GCP Marketplace
      • Vultr
      • DigitalOcean
      • Linode
      • UpCloud
    • Partner Program
      • Partner Program
  • Product
    • Explore Features
      • Everyone
      • Admins & Web Hosters
      • Developers
      • Designers & Agencies
      • Plesk Features
    • Key Topics
      • SocialBee
      • WP Toolkit
      • Sitejet Builder
      • SEO Toolkit
      • Joomla! Toolkit
      • Plesk Premium Email
      • Plesk Email Security
    • Feature Packs
      • Business & Collaboration
      • WP Pack
      • Hosting Pack
      • Power Pack
      • Language Pack
    • Featured Extension
      • SocialBee
  • Pricing
  • Extensions
  • Help center
  • More
    • Careers
    • Events
    • Plesk University
    • Blog
    • Plesk Partner Program
    • Contact Us
  • FREE TRIAL
  • Solutions
    • By Role
      • Developers
      • Content Managers
      • Digital Agencies
      • IT Admins
      • Web Hosters
      • Hyperscalers
    • By Edition
      • Web Admin Edition
      • Web Pro Edition
      • Web Host Edition
      • Business & Collaboration
      • WP Edition
    • By Cloud
      • Amazon Web Services
      • Microsoft Azure
      • Alibaba Cloud
      • GCP Marketplace
      • Vultr
      • DigitalOcean
      • Linode
      • UpCloud
    • Partner Program
      • Partner Program
  • Product
    • Explore Features
      • Everyone
      • Admins & Web Hosters
      • Developers
      • Designers & Agencies
      • Plesk Features
    • Key Topics
      • SocialBee
      • WP Toolkit
      • Sitejet Builder
      • SEO Toolkit
      • Joomla! Toolkit
      • Plesk Premium Email
      • Plesk Email Security
    • Feature Packs
      • Business & Collaboration
      • WP Pack
      • Hosting Pack
      • Power Pack
      • Language Pack
    • Featured Extension
      • SocialBee
  • Pricing
  • Extensions
  • Help center
  • More
    • Careers
    • Events
    • Plesk University
    • Blog
    • Plesk Partner Program
    • Contact Us
  • FREE TRIAL

Knowledge Base

Webmail/domain is unavailable: Server not found

 
dnsdomain namefirewallgooglegoogle chrome

Symptoms

  • When opening webmail/domain in a browser, it returns one of the following errors:

    • Firefox:

      "Server not found. Firefox can't find the server at webmail.example.com"

    • IE:

      "Internet Explorer cannot display the webpage"

    • Chrome:

      "Oops! Google Chrome could not find webmail.example.com"

      OR

      "ERR_NAME_NOT_RESOLVED"

      OR

      "404 not found"

  • Let's Encrypt cannot be issued on the domain:

    Error: Could not issue a Let's Encrypt SSL/TLS certificate for example.com. Authorization for the domain failed.
    <...>
    Details:
    Type: urn:acme:error:connection
    Status: 400
    Detail: Fetching http://example.com/.well-known/acme-challenge/cCMl-4ZDqnWT-DEADBEEFl0sl_z9KVN_Ghkc1f1pMpQ: Timeout during connect (likely firewall problem)

Cause

Webmail/domain does not resolve correctly in global DNS system because Plesk server is not set up to manage DNS.

Resolution

To verify the root cause, run the following commands in a command-line interface:

Note: the commands are identical on Windows, Linux and MacOS. The commands below are valid for webmail as well

  1. First, test if domain can be resolved to an IP address in general:

    C:> nslookup example.com
    Server: mydns.server.com
    Address: 203.0.113.2

    Non-authoritative answer:
    Name: example.com
    Address: 203.0.115.20

    Output explanation:

    • Server and Address represent hostname and address of the server that provides response for the query sent by command nslookup;
    • Name and Address(es) are the domain name which IP address is being queried and the IP address that was provided by the server as a response.

    However, if the following output is seen instead, it means that the domain does not resolve properly:

    C:> nslookup webmail.example.com
    Server: mydns.server.com
    Address: 203.0.113.2

    *** UnKnown can't find example.com: No response from server

  2. Next, check if DNS service on the server with Plesk contains proper record for the domain:

    C:> nslookup webmail.example.com 203.0.115.20 <---- IP address of the server with Plesk
    Server: UnKnown
    Address: 203.0.115.20

    Name: webmail.example.com
    Address: 203.0.115.20

If the first command does not return anything or returns a wrong IP address, and the second command returns valid records, then Plesk server is not serving the DNS zone for a domain.

There are two options to resolve the issue:

  • Set Plesk server to be nameserver of the domain: How to use DNS with a Plesk server;

  • Add a respective A-record on a registrar/3rd-party DNS side.

Note: a similar issue can be observed for other DNS records like TXT, MX, CNAME and etc.

Tweet
Share
Share
Email
0 Shares
Read the full article
Related Posts

DNS_PROBE_FINISHED_NXDOMAIN: What Is It And How To Fix The Problem

Read More »

WordPress Firewall – Why Do You Need One?

Read More »

Podcast | The Keys to Success on the Web with Alberto Medina

Read More »
Knowledge Base

Unable to issue a Let’s Encrypt certificate for a domain or its mail in Plesk: the DNS challenge used another IP address

Read More »

 An operation fails in Plesk: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry ‘X’ for key ‘PRIMARY’

Read More »

A warning is shown while accessing Plesk or webmail: The certificate is not trusted or NET::ERR_CERT_AUTHORITY_INVALID

Read More »

How to install Let’s Encrypt SSL certificate for domain in Plesk?

Read More »

Hosting Wiki

  • DBMS Interface
  • Server Redundancy
  • QMAIL
  • Sendmail
  • Linux Containers
  • Google Cloud CDN
  • Bare Metal Server
  • Oracle VM Server
  • Server Virtualization Software
  • Windows Server
  • Linux
  • JavaScript
  • Domain
  • Plesk
  • Web Server
  • Static DNS
  • DNS Server
  • DNS Forwarding
  • Reverse DNS
  • IPv6
  • IPv4
  • SIP
  • SSL
  • UDP/IP
  • Firewall
  • Email Autoresponder
  • Mailing Lists
  • Email Alias
  • Email Virus Protection
  • Email Forwarding
  • Webmail
  • TCP/IP

Industry
Partners

industry-partner_ALIBABA
industry-partner_GOOGLEPARTNER
industry-partner_MICROSOFT
industry-partner_REDHAT-r2
industry-partner_ALIBABA
industry-partner_AUTOMATTIC
industry-partner_AWS
industry-partner_DIGITALOCEAN
industry-partner_SCALEWAY
Follow us:
Facebook Twitter Linkedin Youtube Github

COMPANY

About Plesk
Our Brand
Legal
Careers
Impressum

PRODUCT

Pricing 
Extensions
What’s new

KNOWLEDGE BASE

Documentation
Help Center
Migrate to Plesk
Contact Us
Hosting Wiki
Preview releases

PROGRAMS

Contributor Program NEW
Partner Program
Affiliate ProgramNEW

COMMUNITY

Blog
Forums 
Plesk University

First defaul

Company

About Plesk
Our Brand
Legal
Careers
Impressum

PRODUCT

Pricing 
Extensions
What’s new

KNOWLEDGE BASE​

Documentation
Help Center
Migrate to Plesk
Contact Us
Hosting Wiki
Preview releases

PROGRAMS​

Contributor Program NEW
Partner Program
Affiliate ProgramNEW

COMMUNITY​

Blog
Forums
Plesk University

Follow us:
Facebook Twitter Linkedin Youtube Github

© 2025 WebPros International GmbH. All rights reserved. Plesk and the Plesk logo are trademarks of WebPros International GmbH.

Managed with love with Plesk WP Toolkit