Every provider quotes a per-inbox price. It tells you almost nothing on its own, because what you need is daily sending capacity, and how much each inbox can safely send varies a lot between providers.
Here is how the arithmetic actually works in 2026.
The three costs
Your infrastructure bill has three parts, and people usually only budget for the first:
- Mailboxes. Priced per tenant on Azure, per inbox on Google.
- Domains. Roughly $10 to $15 a year each, unless they are included.
- Sending platform. Smartlead, Instantly, EmailBison and similar, typically $30 to $100+ a month depending on seats and volume.
What mailboxes cost
| Provider | Price / month | Domain | Safe sends / day |
|---|---|---|---|
| Microsoft Azure | €30 per tenant (25, 50 or 100 inboxes) | Included (.com) | 2 to 3 per inbox |
| Azure pre-warmed | €50 per tenant, minimum 2 | Included | 2 to 3 per inbox, sending immediately |
| Google Workspace | €3.00 per inbox, €2.50 at 500+ | Not included | up to 15 per inbox |
| Google pre-warmed | €8 per inbox | Included | up to 15 per inbox, sending immediately |
On Azure the tenant is the unit you buy: one .com domain and your choice of 25, 50 or 100 inboxes, same price. Google is priced per inbox with the rate dropping as you scale.
Cost per 1,000 emails a day
This is the number that actually matters. Work backwards from your target volume.
On Azure: at 2 to 3 sends per inbox, you need roughly 400 inboxes. That is 4 tenants of 100 at €30, so €120 a month, with 4 .com domains included.
On Google: at up to 15 sends per inbox, you need roughly 70 inboxes. At €3.00 that is €210 a month, plus about 24 domains at 3 inboxes each, which you buy separately.
Azure comes out cheaper, and the gap widens as you scale because the domain is bundled. The estates look different though: 400 Azure inboxes across just 4 domains, versus 70 Google inboxes spread across 24.
The cost people forget
Mailbox reputation decays. Domains age, sending patterns get stale, and placement drifts down over months. The infrastructure that worked in January quietly underperforms by June.
Most people discover this when reply rates halve and they blame the copy. The real fix is rotation: replacing sets on a schedule before decay shows up in your numbers. A new set is ordered at week four, warms for two weeks while the current set keeps sending, then takes over at week six while the old set is cancelled. Budget for roughly one set turning over every six weeks rather than treating infrastructure as a one-time purchase.
Done-for-you versus doing it yourself
If you are running this yourself, the numbers above are your bill plus your time: buying domains, configuring DNS, warming, connecting to a sending platform, and monitoring placement.
Our Build and Release packages exist because most teams would rather skip that. €1,000 a month covers 500 Azure accounts, 10 domains and 2,000 emails a day. €1,700 covers 1,500 accounts, 30 domains and 6,000 a day. Both include copy written for your business, campaign buildout, SmartLead access and the first month of leads (usually 5-7k on Basic, 8-10k on Advanced), and the system is handed to you after 14 days.
What to actually budget
- Testing the channel: around €100 to €250 a month of infrastructure plus a sending platform. Enough to prove whether cold email works for your offer.
- Running it seriously: roughly €350 to €1,200 a month of infrastructure at 3,000 to 6,000 sends a day, plus rotation.
- Not wanting to touch it: €1,000 to €1,700 all in, done for you.
Want this done for you?
Our Build and Release service stands up your entire cold email infrastructure: domains, mailboxes, authentication, warm-up, and tracking, all authenticated and ready to send. You skip the weeks of setup and start with campaigns.
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