Term
DNS
The system translating a domain name into a server address. A DNS mistake takes down both site and company e-mail.
Updated
What it means
DNS translates a domain name into a server’s IP address. When someone types your web address, the browser first asks DNS where to connect - and only then does the page load.
DNS records govern more than the website. A and AAAA point to hosting, MX to the mail server, and TXT carries domain verification plus SPF, DKIM and DMARC, which stop your domain being used in fraudulent e-mail.
The domain, DNS and hosting are three separate services that may sit with three different companies. The registrar holds the domain, the DNS server says where it points, and the host serves the website itself. In an outage you need to know which one failed, or the fault is sought in the wrong place and the fix takes longer than it should.
How it works in practice
The domain belongs to the company, not to the supplier. The registrar account, DNS access and the contact address should be in the company’s name - otherwise changing agency means losing control of both the site and the mail.
Record changes do not take effect instantly: TTL sets how long servers remember the old value. That is why moving an online store or mail service is planned with slack and outside peak hours.
When a company e-mails invoices straight from its invoicing or accounting software, that software’s sending server must be listed in the domain’s SPF record. Otherwise invoices land in customers' spam folders or are never delivered, and the company finds out only once they are already overdue.
What to watch out for
An expired domain is the quietest disaster there is: the site vanishes, mail stops arriving, and recovery after the deadline is expensive or impossible. Auto-renewal and a monitored contact address cost less than any remedy - the same as with an SSL certificate.
Whoever gains access to DNS management can redirect the company’s mail to their own server and read it, password resets included, or send out invoices with a changed bank account number. The registrar account is therefore one of those that should have two-factor authentication switched on.
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