Domains, delivery and craft
What is Nameserver?
The servers that hold the authoritative DNS records for a domain. Changing nameservers moves the entire zone to a different provider, which is a much larger change than editing a single record and is the usual reason email breaks during a website move.
Also called: NS record · authoritative nameserver
Changing them safely
- Export the full existing zone first, every record type
- Recreate every record at the new provider before switching
- Verify the MX records especially — email failure is the usual casualty
- Change the nameservers at the registrar
- Confirm resolution and mail delivery from outside your own network
Why email is what breaks
A new provider starts with a default zone containing only web records. Switch nameservers before recreating the MX, SPF and DKIM entries and mail stops arriving immediately, silently, and for everyone. It is the most common self-inflicted outage in a hosting move.
When you do not need to change them
Moving hosts usually needs only an A record update. Changing nameservers is for changing DNS provider, which is a separate decision that does not have to happen at the same time — and generally should not.
Where this is covered in depth
A definition can only go so far. Migrating a site without losing what it took years to earn covers this properly — 3 minutes, free, no email required.
Who wrote this
Anas Bin Masud builds e-commerce sites and does technical SEO for businesses in the UK, Canada and Pakistan. These definitions come from client work rather than from a content brief — where an entry describes a mistake, it is usually one found on a real site. More about how I work.