What Is an Email Domain? How to Get Your Own

An email domain is the part of an email address after the @ sign. In [email protected] the email domain is example.co.uk, and in a personal Gmail address it is gmail.com, which belongs to Google.

An email domain of your own is a name you register and point at the services you pick. It puts your business name in every address, lets you publish the records that inboxes check, and stays yours when you change provider.

For a newsletter it is close to required: most free addresses are refused or sent to spam when a mailing platform sends for them.

Email domain examples: free and your own

Every email address has two parts joined by the @. The local part names the mailbox, and the email domain names who handles mail for it. The email message standard, Request for Comments (RFC) 5322, defines an address in exactly these two parts.

The domain is also where DNS (Domain Name System) records live. DNS is the public directory that tells other servers where your mail goes and how to check it.

Address	Email domain	Who controls the domain	Can you add DNS records to it?
[email protected]	gmail.com	Google	No
[email protected]	btinternet.com	BT, the broadband provider	No
[email protected]	example.co.uk	You, as the registered holder	Yes
[email protected]	news.example.co.uk, a subdomain	You, or the platform you hand it to	Yes

The last column decides most of what follows. Inboxes judge an email against records published on the sender's domain, and only the holder can publish them.

Why a free address can't send your newsletter

Free email providers publish a policy telling other inboxes what to do with mail that uses their domain but did not come from their servers. A newsletter platform sends from its own servers, so a free address in the From line fails that check.

The policy sits in a DMARC (Domain-based Message Authentication, Reporting and Conformance) record. It asks inboxes to refuse failing mail (p=reject), file it as spam (p=quarantine) or take no action (p=none).

Anyone can read these records, which are TXT (text) records in DNS, with one command. Here is BT's:

dig +short TXT _dmarc.btinternet.com
"v=DMARC1; p=reject; sp=reject; pct=100; fo=1; rua=mailto:[email protected]; ruf=mailto:[email protected];"

We ran the same lookup on the free email domains of the large UK broadband and webmail providers on 25 October 2026.

The right-hand column shows what an inbox that follows DMARC does with a newsletter from that address, sent through a platform.

Free email domain	DMARC policy	Newsletter sent through a platform
btinternet.com, sky.com, talktalk.net, virginmedia.com	p=reject	Refused
yahoo.co.uk, yahoo.com, aol.com	p=reject	Refused
icloud.com, googlemail.com	p=quarantine	Sent to spam
gmail.com	p=none	Temporary failures for bulk senders, under Google's own rule
hotmail.co.uk, hotmail.com, live.co.uk, outlook.com	p=none	Cannot pass DMARC, which the bulk sender rules require

Yahoo's policy guides receivers, Gmail and Hotmail included, to reject mail that may not be legitimately sent by Yahoo (Yahoo Sender Hub).

The p=none rows do not open a door either. Google's FAQ calls a @gmail.com From address on mail sent from outside Gmail's servers "spoofing". Bulk senders doing it "will start getting notifications about temporary failures" (Gmail sender guidelines FAQ).

Google's guidelines also say Gmail "will begin using a DMARC quarantine enforcement policy" (Gmail email sender guidelines). On the night of our lookup, the gmail.com record still read p=none.

Hotmail and Outlook addresses fail the bulk sender requirements instead. Senders of 5,000 or more emails a day to Gmail must pass DMARC. For that, the From domain must match the domain that signed or sent the mail. Yahoo sets the same rule for every bulk sender (Yahoo sender requirements), and only Microsoft can sign or send mail as hotmail.co.uk.

For a plumbing firm in Peterborough (our example) that has written to customers from a btinternet.com address for years, the first row settles it. Its newsletter needs an email domain of its own, even if daily email stays in the old inbox for now.

Some platforms work round the problem by swapping your free address for one on their own domain. The newsletter then arrives, but your customers see the platform's name after the @ instead of yours.

Email domain, mailbox and sending: three separate jobs

Registering an email domain gives you the name and nothing else, not even one mailbox. Email on your own domain needs up to three services, and three different companies can provide them.

Job	Who does it	What it adds to your DNS	Examples
Holds the name for you	A domain registrar	Nothing by itself; your DNS settings usually live there	Registrars that sell .uk names
Runs the mailboxes you read and reply from	A mailbox host	A TXT record to prove ownership, then MX (mail exchange) records	Google Workspace, Microsoft 365
Sends newsletters and campaigns	An email platform	Sending records, or a subdomain handed over to it	MailGraf and other email marketing platforms

Google's own glossary draws the same line. A registrar sells names nobody owns yet, and a domain host runs the DNS servers that hold your records. Most companies do both (Google Workspace Admin Help).

The mailbox host tells other servers to deliver your mail to it through an MX record. For Google Workspace that record points at smtp.google.com.

Should your UK email domain be .co.uk or .uk?

Either works for email. Pick the ending your customers will type without thinking. If the other one is still available, register it too, so nobody else can use your name.

Nominet runs the registry for every .uk name. It calls .co.uk "the original domain for British business online" and opens the shorter .uk to businesses and individuals alike (The UK Domain).

The same site quotes a 2021 survey Yonder ran for Nominet, in which 91% of people associated .co.uk with safety (The UK Domain).

Nominet does not sell names to the public. Its comparison tool lists registrars, and you buy the name from one of them. You renew it every year, so a domain of your own is never free.

If someone else already holds the .uk version of your .co.uk name, there is a reason. Holders of a .co.uk registered before 28 October 2013 could claim the matching .uk until 25 June 2019. Unclaimed names then went to whoever registered first (Nominet).

How to get an email domain

Setting up a custom email domain takes six steps, and each one depends on the step before it.

1. Choose the name. Build it from your business name, keep it short and avoid hyphens. Check that it is free with a registrar's search or Nominet's comparison tool.
2. Register it in the business's name. The holder recorded at the registrar owns the domain. Make that you or your company, not the web designer who set it up.
3. Pick a mailbox host and prove you own the domain. Google Workspace and Microsoft 365 each give you a TXT record to add at your DNS host. On Google, an account whose domain stays unverified is deleted within 21 days of sign-up, unless billing is active (Google).
4. Create the mailboxes, then change the MX record. If the domain already receives email somewhere, Microsoft advises adding users and mailboxes first, so mail keeps arriving during the move (Microsoft Learn). Google says a new MX record can take up to 72 hours to be recognised.
5. Authenticate the domain for everyday mail. Your mailbox host supplies the SPF and DKIM records, and you add a DMARC record that starts at p=none. The SPF, DKIM and DMARC setup goes through each record.
6. Give marketing email its own subdomain. Set up news.example.co.uk or similar in your email platform, as the next section explains.

Why marketing email goes out from a subdomain

A subdomain such as news.example.co.uk gives campaigns their own name and their own DNS records, while your mailboxes keep the main domain.

With NS (nameserver) records, you can hand the subdomain to the platform. The platform then manages its sending records, and the records your website and mailboxes depend on stay untouched.

The split also keeps one kind of message on one address. Google's sender guidelines say messages of the same category should have the same From address. A news subdomain makes that line easy to see.

A subdomain is no way round the rules, though. Gmail counts mail from news.example.co.uk and example.co.uk together towards its 5,000-a-day bulk sender threshold.

Your email domain in MailGraf

Under Settings > Senders, MailGraf can send from your root domain, from your subdomain or from a MailGraf domain. None of the three creates a mailbox. Replies go to a mailbox you already have, such as one at the host from step 3, set in the campaign's Reply-to field.

Handing over a subdomain, as described above, is the Your subdomain option. MailGraf's help recommends it for a domain you own, and it takes 4 NS records at your DNS host (Add a sending domain).

A MailGraf domain is the platform-domain route described earlier: your brand name goes in front of postgraf.net, so the address ends in our domain. Frequent domain changes can affect sending reputation, so a business registering its own name this month does better to wait for it.

With the domain registered and the mailboxes working, create your MailGraf account from the pricing page and connect news.example.co.uk as your sending domain.