Email hosting for multiple domains: how it works and what it costs

To run email on several domains you need three things: a provider that accepts every domain, a way to give each domain its addresses without paying for each one, and four DNS records (MX, SPF, DKIM, DMARC) on every domain. Providers differ mostly in what they charge for: each user (Google Workspace, Microsoft 365, Proton), each mailbox (SuperMailOS), or how much the whole account sends (Migadu). Purelymail is a flat $10 a year. Every provider fact below comes from that provider’s own pages, checked 14 Oct 2026.

What are the ways to host email for several domains?

1. A separate account for each domain. Simple to reason about and fully separate, but every account is its own bill, login and admin, and the costs add up per account.
2. One account that holds every domain. The usual answer. On Google Workspace a user alias domain gives every user an extra address at another domain, and a secondary domain has its own users (up to 600 domains in all). Microsoft 365 typically takes up to 5,000 domains. SuperMailOS puts every domain’s mail in one inbox, with replies going out from the address each message came to.
3. An account priced by volume, or flat. Migadu charges one price per account by daily sending ($19 to $990 a year) with unlimited addresses and domains; Purelymail charges $10 a year with no hard limits.

A fourth option, forwarding every domain into one personal inbox, works for receiving but not for replying from the domain’s address, and forwarded mail can fail SPF at the next hop. More in the questions below.

What does each provider allow per domain and per address?

Which DNS records does every domain need?

• MX says which servers receive the domain’s mail.
• SPF lists the servers allowed to send as the domain.
• DKIM publishes the key that verifies the signature on each message.
• DMARC tells receivers what to do when SPF and DKIM don’t line up, and where to send reports.

Every domain needs its own set, and a mistake on one domain affects only that domain. On SuperMailOS the records come from the mail server’s own zone and are checked live before a domain can send; they’re set in one click on Cloudflare, DigitalOcean, Linode, Vultr, Hetzner DNS and Spaceship. The email DNS records guide explains each one, and the free email checker shows what any domain publishes today.

How do you reply from the right domain’s address?

With aliases, the reply should leave from the address the mail came to, not your main one. In SuperMailOS that happens by default: answer a message sent to hello@ on one domain and the reply goes out from that address. Elsewhere it’s usually a per-alias “send as” setting worth checking before you rely on it.

How much does email for several domains cost?

For 4 people on 2 domains, billed yearly, cheapest first (US dollars before tax). The email cost calculator does the same for your own team.

When is one inbox for every domain the wrong choice?

• Each domain has its own team and admin. Separate accounts keep permissions and billing apart.
• You live in a suite. If your team uses Docs and Drive or Microsoft’s apps, the per-user price buys more than mail.
• You send bulk or cold email. That needs a sending platform; business mailboxes, ours included, aren’t built for it.
• Budget is the constraint. Purelymail, Migadu, or Zoho’s free plan (up to 5 users on one domain) cost less than SuperMailOS.

Questions