Custom Domain Email: What It Costs and How to Actually Set One Up

You bought the domain eighteen months ago. At checkout the registrar offered you custom domain email for a few dollars a month, you clicked past it because you were in a hurry, and you've been sending invoices from a gmail.com address ever since. Then a client replied asking whether the invoice was legitimate.

That's the moment most people go looking for this.

The good news: the domain you already own is the whole prerequisite. No website needed, no second domain, and no deep DNS knowledge — you publish four records and know which port to use. The annoying news is that pricing here is confusing on purpose, because most of the market bills per person and quotes per month.

We build JustEmails at Velocity Digital Labs, so we have a horse in this race. We'll flag the bias where it matters, including the part where we're the wrong answer for some of you.

What you're actually buying

Two separate things get sold under the phrase custom domain email, and conflating them is where budgets go wrong.

Mailbox hosting is the inbox. Mail arrives, sits on a server, and you read it in a client or webmail. This is what you want for hello@yourbusiness.com.

Transactional sending is your app emailing your users — password resets, receipts, alerts. Same protocol, completely different shape: no inbox, an API instead, and volume that dwarfs anything a human types.

Most people need the first and eventually discover they need the second. A few hosts bundle both; most make you buy Resend or Postmark or SES separately. Worth knowing before you pick, because migrating twice is its own tax — we broke that math down in what switching email providers really costs.

What custom domain email costs in 2026

Here's the split that matters: some hosts charge per person, some charge per account.

Per-user pricing, as listed on each vendor's own pricing page in September 2026:

• Google Workspace Business Starter — $7.00/user/month list, so $84/user/year. A 30% promotion runs to 23 December 2026, which means a new signup currently sees $4.90 at checkout and the full $7.00 on renewal. Budget against the list price.
• Microsoft 365 Business Basic — $7.00/user/month list. That went up from $6.00 on 1 July 2026 per Microsoft's own licensing notice, so a lot of blog posts still quote the old number. Ours did too, most of this summer, on a page whose entire job was getting competitor prices right. Existing customers keep the $6.00 rate until their next renewal, which is why you'll find people swearing blind that both figures are correct.
• Fastmail Standard — $5/user/month.
• Zoho Mail — $1/user/month on the cheapest paid tier, and they still run a free tier for a handful of users on one domain. Genuinely the cheapest honest answer for one person who doesn't need throughput.

Flat-rate pricing, same date:

• JustEmails — $49/year, one plan, annual only. Unlimited domains, unlimited email accounts, 10 GB of pooled storage.
• MXroute Small — $59/year. Ladder runs $59/$69/$79 and only storage changes between rungs.
• Migadu — tiered by send volume, and the tier is the whole story. Micro is $19/year but caps at 20 sends a day; Standard at $290/year is the rung whose 500/day matches ours. Comparing against Micro without saying "20 a day" is how people end up surprised.

What grates about this whole category is the unit games. Per user. Per month. Billed annually. Three different denominators inside one sentence, and by the time you've normalised them onto a single number you've spent twenty minutes doing arithmetic the vendor could trivially have done for you and chose not to.

The crossover is early. One person on Google Workspace is $84/year against $49-59/year flat — close enough that features decide it. Three people is $252/year against the same $49, and the shape of the bill starts mattering more than the brand. An agency holding fifty client domains isn't in the same conversation at all; we ran that arithmetic in the 50-domain agency cost breakdown.

The contrarian bit: if you're one person on one domain and you already want Docs and Drive, Google Workspace bundles those and we do not — the flat-rate case only starts paying once the second domain arrives. The $35/year you'd save on a flat plan isn't worth an afternoon of your time. Flat-rate hosting earns its keep at the second domain, or the second person, or the first API key — not before. (We'd rather tell you that than sell you a $49 plan you resent.)

The records you publish

The DNS side of custom domain email is nearly identical across every host. Four records, one purpose each.

MX — where mail for your domain gets delivered. Priority plus a hostname. On JustEmails it's a single record:

Type  Host  Priority  Value
MX    @     10        mail1.justemails.app

One record. If a guide hands you a second "backup" MX at priority 20, check that something real is behind it — a backup MX pointing at nothing is a documented path for spam to reach you, which is worse than having no backup at all.

Delete your old MX records first. Leaving a previous provider's MX alongside a new one means some mail goes to the dead inbox and some doesn't, intermittently, in a way that takes days to notice. It's the single most common setup failure we see people describe, and I say that as someone who did it to one of our own internal domains and then spent a cheerful afternoon building a case that the new host was silently dropping mail. It wasn't. I was.

SPF — which servers may send as your domain. One TXT record per domain, no exceptions:

Type  Host  Value
TXT   @     v=spf1 a:mail1.justemails.app ~all

Note there's no include: in ours. That matters more than it looks: an include: pointing at a hostname with no TXT record authorises exactly zero IP addresses, so SPF fails while your DNS panel shows a perfectly formatted record. If you're already sending from other services, merge them into this one record rather than adding a second.

DKIM — a cryptographic signature proving the message wasn't altered. The host generates the key; you publish the public half. We generate and publish this for you when the domain verifies, along with DMARC and MTA-STS, so on JustEmails this step is a checkbox rather than a copy-paste of a base64 blob long enough to wrap six times in your DNS panel.

DMARC — what receivers should do when the first two fail, plus reporting so you can see who's sending as you. Start at p=none, read the reports for a few weeks, then tighten. Do not open with p=reject; you'll bounce your own mail the first time something's misconfigured. The full ramp is in going from p=none to p=reject without breaking your email.

Connecting a client

Every mainstream client wants the same four facts, and one of them is where people get stuck.

Username is the full email address. Password is the mailbox password.

Three things worth saying plainly, because each of them has burned someone:

• It's mail., not smtp. or imap. Those hostnames don't exist and never did. They fail at name resolution, before TLS, which means you see a timeout rather than an error that tells you anything.
• Port 587 with STARTTLS. Not 465. 465 is closed here. It's a real port at other providers, so half the tutorials on the internet will tell you to use it. Honestly, 465 should have been retired from documentation a decade ago. It survives because tutorials copy tutorials, and nobody writing the ninth one ever goes back to check which ports their host actually answers on.
• There are no app-specific passwords to generate. IMAP and SMTP authenticate with the mailbox password itself, and auth is PLAIN or LOGIN — a tool defaulting to CRAM-MD5 will fail. (App passwords from Google or Zoho are a real thing you'll need in the other direction, when you're importing old mail from them.)

Max message size is 25 MB, which is also the API's limit. Fine for contracts, not fine for the video someone will inevitably try to attach.

The limit nobody mentions

Here's the part that makes people think a working custom domain email setup is broken, and it's true in some form at every host on earth.

New sending domains are rate-limited. On JustEmails a freshly verified domain is capped at 50 sends a day for its first week, 200 a day in the second week, and 500 a day from day 15. Separately, a brand-new account is held to 20 a day for its own first week. Both apply; the lower one wins. So a signup-day reader publishing their records at 11pm is working with 20 sends, not 500.

Nothing is broken. You're just early.

Three details that catch people:

1. The clock starts at domain verification, not signup.
2. The cap belongs to the account, not a mailbox — ten mailboxes share one allowance.
3. API sends draw on the same daily number. The included quota is 1,000 transactional emails a month, and each $25/year tier adds 10,000 to the monthly quota — but the daily ceiling doesn't move, which puts the honest practical maximum around 15,000 a month. Buying nine tiers doesn't buy 91,000 deliverable emails. We'd rather you know that before the invoice than after.

Which also means: this isn't a newsletter backend. The SMTP config connects to Listmonk or Mautic happily and then hits a wall. If bulk is the job, use a bulk ESP.

Before you call it done

Send one message out and one in, then check the headers. In Gmail: three dots → Show original, and look for SPF, DKIM and DMARC all reading PASS. MXToolbox will read your records back in plain English for free, and it catches the two classic typos — a duplicate SPF record and a missing underscore in _dmarc.

Then the thing almost nobody does: check again in six months. Records get clobbered. Somebody adds a marketing tool that rewrites SPF, or moves the domain to a new registrar and the TXT records don't come along. We monitor verified domains continuously and email you when SPF, DKIM, DMARC or MX drifts from what we verified — a drift alarm is the feature nobody shops for and then relies on.

A few other things in the box that rarely make comparison tables: MTA-STS and DANE/TLSA per domain, BIMI with VMC support, DKIM key rotation that keeps the previous key live so mail already in flight still verifies, blocklist monitoring across five DNSBLs, and RFC 8058 one-click unsubscribe with a suppression list enforced at send time.

And the honest gaps: no calendar, no contacts, no native mobile apps, no SSO/SAML, and sending is from shared infrastructure — dedicated IPs aren't offered. If any of those is load-bearing for you, buy elsewhere. If your problem is "I own four domains and I'm tired of paying per person for each," the flat plan is the whole pitch, and consolidating onto one host is covered in running mailboxes and an API on a single host.

Frequently Asked Questions

How do I get a custom email from my domain?

Three steps. Pick a mail host, publish the DNS records it gives you (an MX record so mail reaches it, plus SPF, DKIM and DMARC so receivers trust it), then create the mailbox and connect a client over IMAP and SMTP. The domain you already own is enough — you don't need a new one, and you don't need a website. Hands-on time is about 30 minutes, and DNS propagation usually adds under an hour.

How much does custom domain email cost per year?

Per-user hosts charge per person: Google Workspace Business Starter lists at $7.00/user/month and Microsoft 365 Business Basic at $7.00/user/month as of September 2026, so one person is roughly $84/year and five people is $420/year. Flat-rate hosts charge per account instead — JustEmails is $49/year for unlimited domains and unlimited mailboxes, MXroute's Small tier is $59/year. Domain registration is separate, usually $10-15/year.

Can I keep using Gmail with a custom domain address?

Yes, if your host offers plain IMAP and SMTP. In Gmail, Settings → Accounts → "Check mail from other accounts" pulls the mail in, and "Send mail as" sends replies from the custom address. With JustEmails you point both at mail.justemails.app — IMAP on 993, SMTP submission on 587 with STARTTLS — and authenticate with the full email address and the mailbox password.

Why do my first emails from a new domain fail or get limited?

New sending domains are rate-limited everywhere, including here. On JustEmails a freshly verified domain is capped at 50 sends a day for its first week, 200 a day in the second week, and 500 a day from day 15, and a brand-new account is held to 20 a day for its own first week — the lower of the two applies, and API sends draw on the same daily allowance. Nothing is broken; you're inside a ramp.

Where to go next

If you want the line-item version of the pricing above, including registrar costs and the per-user math at team sizes, that's what a custom domain email address really costs. If you'd rather see the DNS side in more depth, the full setup guide walks the records for Google, Microsoft and Zoho alongside ours.

Every inbox behind our own products — ClickzProtect, JustAnalytics, the rest — runs on this. Trial is 7 days. Transactional API access is on the paid plan, so build against it there. Enough to prove the mail flows. Not enough to build an integration against, which we'd rather say here than let you find out on day three. Refunds run 14 days from the first charge.

Questions are best sent from the site itself, where they reach someone who can actually look at your account — or read the rest of the JustEmails blog.

Try JustEmails

Unlimited custom domain email hosting for $49/year flat — unlimited domains, unlimited mailboxes, 10 GB storage, full IMAP/SMTP. Built for agencies, freelancers, and anyone managing email across more than one domain.

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