InboxKit sells Google Workspace and Microsoft 365 mailboxes at one flat rate: $3.00 a mailbox a month, or $2.50 on annual billing, with no plans, base fee or minimum. Azure is $30 a tenant for up to 100 mailboxes. Warm-up is a $3 per mailbox add-on, and pre-warmed mailboxes run $6 to $9 depending on how long they have been warmed. It has a REST API and an MCP server.
That is a good deal for a lot of senders. Here is where other providers fit better, with every fact taken from the provider's own site in October 2026.
The alternatives at a glance
| Provider | Microsoft | Domain in the price | Pre-warmed | Done-for-you | |
|---|---|---|---|---|---|
| Frostmailer | €30 per tenant, 25, 50 or 100 inboxes | €3.00 to €2.50 | Yes on Azure (.com) | Azure €50 per tenant, Google €8 with domain | Yes, from €1,000 a month |
| Primeforge | M365 $4.50 per slot | $4.50 per slot | No, $14 a year | Listed, no price | No |
| Hypertide | Entra $25 per domain, 25 inboxes | $3.30 | Yes on Entra | Not listed | No |
| ScaledMail | Outlook $50 per domain, 25 mailboxes | $3.50 | Yes on Outlook | Pre-warmed domains, no price | Setup done for you |
| Zapmail | M365 per seat | Per seat | No | Yes | No |
| MailDeck | Outlook $30 to $40 per tenant, 100 inboxes, minimum 2 | Plans from $39 for 10 | No, bring your own | Outlook $40 per tenant | No |
| Premium Inboxes | Same tiers as Google | $3.50 to $2.80 | No, bring your own | Not a separate product | Managed tier, $7,500 a month |
1. Frostmailer: if you send mostly to Outlook, or want it built for you
A Frostmailer Azure tenant is €30 a month for a .com domain plus 25, 50 or 100 inboxes, so the domain is part of the price rather than a separate line. Each inbox sends 2 to 3 emails a day. Pre-warmed Azure is €50 a tenant and pre-warmed Google is €8 an inbox with the domain included, both with four weeks of warm-up done before delivery. Google Workspace full admin is €3.00 to €2.50 per inbox with your own domains.
The bigger difference is Build and Release: from €1,000 a month we set up domains, mailboxes, DNS, warm-up, copy and campaigns, include the first month of leads, and hand the system over after 14 days. InboxKit focuses on self-serve and does not list a done-for-you build.
2. Primeforge: if you want the Forge ecosystem
Real Google Workspace and Microsoft 365 mailboxes at $4.50 a slot, minimum 10 slots, with domains at $14 a year. It sits alongside Mailforge, Infraforge, Warmforge and Salesforge, which is the main reason to choose it.
3. Hypertide: if 25 Microsoft inboxes per domain is enough
Entra at $25 a domain a month, 25 inboxes, domain included, set up in 4 to 6 hours. Google Workspace is $3.30 an inbox.
4. ScaledMail: if you want setup handled
Google at $3.50 a mailbox and Outlook at $50 a domain for 25 mailboxes with the domain included. ScaledMail says it does DNS, domains and inbox setup for you, with delivery quoted at 24 to 72 hours.
5. Zapmail: if you want pre-warmed Google and add-ons
Per-seat Google and Microsoft mailboxes, pre-warmed inboxes, an API and an MCP server. The setup keeps your nameservers with Zapmail. Zapmail merged its Google and Microsoft plans on 13 October 2026, so check its site for current prices.
6. MailDeck: if you also want SMTP
Outlook tenants of 100 inboxes from $30 to $40 a month with a minimum of 2 tenants, pre-warmed Outlook at $40 a tenant, and private SMTP. You bring your own domains, and Outlook delivery takes 2 to 3 business days.
7. Premium Inboxes: if you replace inboxes often
Google and Microsoft at $3.50 to $2.80 per inbox with unlimited replacement inboxes. You bring your own domains.
Which one should you pick?
- Want the domain in the price: Frostmailer (Azure), Hypertide (Entra) or ScaledMail (Outlook).
- Want pre-warmed with the domain included: Frostmailer.
- Want it built for you: Frostmailer's Build and Release, or ScaledMail for setup only.
- Happy to self-serve and want no minimum: InboxKit is hard to beat.
Sources, checked October 2026: inboxkit.com/pricing and inboxkit.com, primeforge.ai/pricing, hypertide.io/entra, hypertide.io/google, scaledmail.com/pricing, zapmail.ai and its help centre, maildeck.co, premiuminboxes.com/pricing-page. Prices are in each provider's own currency and change often, so check before buying. See also our comparison pages for Zapmail, Hypertide, MailDeck and Premium Inboxes.
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