Business Email Cost Per Domain: The Real 2026 Math

Every email provider publishes a price per user. Almost nobody publishes a business email cost per domain, which is the number you actually need if you own five domains and want a working support@ on each one. So we sat down with the current pricing pages and did the division. Below is what one real mailbox per domain costs in 2026 across eight providers, the two flat-rate hosts that beat everyone on raw price, and the costs that never appear on a pricing page at all.

How to work out business email cost per domain

Providers price per seat, and a seat is one identity on one domain. To turn that into a cost per domain you need a scenario, so here is the one we used throughout: one person, five domains, one real mailbox on each. No team, no shared seats, just five addresses that can receive mail and answer it as themselves.

That is the setup most people searching for this actually have. A main product, a side project, a client brand, two domains bought for ideas that might happen. Four of the five get almost no mail, which is exactly why paying full seat price for each one stings.

One caveat before the table: aliases do not count. Google and Microsoft both let you bolt extra domains onto a single seat for free, but an alias is another address pointing at the same identity, not a separate mailbox. If free aliases solve your problem, your cost per domain is close to zero and you can stop reading. This table is for people who want the domains actually separated.

The 2026 cost per domain table

Prices verified against vendor pricing pages on 4 August 2026. All figures are annual billing, which is the cheaper option everywhere.

A few notes so the numbers are honest. Fastmail publishes in euros, so we left it in euros rather than inventing a conversion. Zoho's own pricing page did not render prices for us on the day of writing, so the roughly $1 Mail Lite figure comes from third-party pricing trackers and should be checked against Zoho directly before you commit. And Google Workspace and Microsoft 365 are suite bills, not email bills: that $84 per domain is also buying Drive, Docs, Meet or the Office equivalents, which we broke down properly in the Google Workspace multiple domains pricing post.

The spread is the interesting part. The same job costs $2 or $84 per domain per year depending entirely on whether the provider prices per seat or per account.

The flat-rate hosts that break the per-seat math

Two names in that table are not playing the same game, and if you are optimising purely for price you should know about them.

Migadu charges per account, not per mailbox. One flat fee covers unlimited mailboxes across effectively unlimited domains. Mini is $90 a year with 30 GB of storage. The catch is the sending quota: Mini allows 100 outgoing messages a day, and the $19 Micro plan allows only 20 outgoing and 200 incoming per day, account-wide. For a handful of low-traffic project domains that is plenty. For anything with real support volume it is not.

Purelymail is the cheapest thing in the table by a wide margin. The Simple plan is $10 a year with no hard limits on users, custom domains or storage. It is a small, no-frills operation, and the interface reflects that, but the multi-domain math is unbeatable.

Both are genuinely good answers to "cheapest email hosting for multiple domains", and we would rather say so than pretend otherwise. If your only requirement is a mailbox per domain at the lowest possible number, go look at them. What neither gives you is a single inbox that shows every domain's mail together and tags which brand each message hit, or an API your apps can send through. You get IMAP accounts, one per address, and you point a mail client at them. That is a different product, and we compared the client options in best email client for multiple accounts.

The costs that never show up on a pricing page

Three real costs are missing from every table above, including ours.

The reply problem. The cheap route people actually take is not Migadu, it is free forwarding into a personal Gmail, which shows a cost per domain of $0. That holds until you hit reply and the answer leaves from your personal address instead of the domain the mail arrived on. Since 2024 the large mailbox providers filter or bounce outbound mail that fails SPF, DKIM and DMARC for the domain in the from line, so Gmail's Send-As patch is no longer a reliable fix. A $0 setup that quietly drops replies into spam is the most expensive option in the list. The full explanation is in how to reply to email from a custom domain, and the Cloudflare-specific version is here.

Transactional sending. If any of those domains ship receipts, password resets or notifications, none of the mailbox hosts above cover it. You add Resend, Postmark or Mailgun on top, which is a second bill and a second DNS setup per domain. Price the pair, not the mailbox alone.

Setup and maintenance time. Every domain needs its DNS records added and verified, and every provider needs a separate login to keep an eye on. Five domains across two vendors is ten setups and two dashboards. That time is real even though it never appears as a line item, and it is the reason a lot of people end up back on forwarding. If you are weighing that trade-off, email hosting for multiple domains walks the routes in more detail, and email forwarding service covers where the free tier stops.

Where Mailyond fits in this table

We are not the cheapest row and we are not going to claim to be. Purelymail is $2 a domain a year and Migadu is $18. Mailyond's Basic plan is $10 a month covering up to five domains, so $24 per domain per year, with 3,000 sent and received messages included. The Agency plan is $40 a month for up to 30 domains, which is $16 per domain per year.

What that price buys that the cheaper rows do not is the second half of the job. Every connected domain's mail lands in one inbox, tagged by domain, so you read all five in one list instead of five IMAP accounts. Replies go out authenticated as the address the message came to, so they pass DMARC without a Send-As workaround. And there is a REST API on the same plan for the transactional mail those domains send, so the second bill and the second DNS setup do not happen. The API is Resend-compatible, which means existing send code changes one line.

Each domain is one 5-minute DNS setup: a DKIM TXT record, a Return-Path CNAME and an MX record, verified in the app, after which that domain both receives and sends signed mail. Your main email stays where it is, since Mailyond runs alongside Gmail or Workspace rather than replacing them.

The honest version of the comparison: if you want the lowest possible cost per domain and you are happy managing mailboxes yourself, take Purelymail or Migadu. If the per-domain cost you care about includes the reply half and the sending half, compare the $24 against a mailbox host plus a transactional provider, which is the fair fight. Plans are on the pricing page, and there are 7 days free if you want to run the numbers against your own domains.

The short version

Business email cost per domain in 2026 ranges from about $2 to $84 a year for the same job, and the only thing that moves the number that much is whether the provider bills per seat or per account. Google Workspace and Microsoft 365 land at $84 per domain because you are buying a suite seat to get a mailbox. Zoho drops that to around $12. Flat-rate hosts like Migadu and Purelymail ignore the seat model entirely and land between $2 and $18, with sending quotas to check.

Then add the things the table leaves out: authenticated replies, transactional sending, and the per-domain setup time. Price all three together and the cheap rows get closer to the expensive ones than they look. Mailyond sits in the middle of that table on purpose, because it is priced for all three at once.