COMPARISON
Premium Inboxes alternative: 100 Microsoft 365 inboxes for $30, not $350
Premium Inboxes and coldemailinboxes.io agree on more than most pairs here: both sell Google and Microsoft inboxes, both verify DNS before handover, and both work to 15 sends a day for a Google inbox. The gap is the Microsoft price, and what each includes around the inbox.
Disclosure: we are coldemailinboxes.io, one of the two vendors compared. Every figure for Premium Inboxes is from their own public pages, linked at the bottom.
The two offers side by side
| coldemailinboxes.io | Premium Inboxes | |
|---|---|---|
| Published price | $30 / domain / month for 100 Microsoft inboxes ($0.30 each) · Google $3 / inbox / month | $3.50 / inbox (1-249), $3.00 (250-1,249), $2.80 (1,250+), same on both platforms |
| Insured tier | None | $4.50 / inbox |
| Platforms | Microsoft 365 and Google | Google and Microsoft |
| Mailboxes per domain | Microsoft 100 · Google up to 3 (our limit, not Google’s) | Not stated as a rule; their calculator uses 3 |
| Sends per inbox per day | Microsoft 3 / inbox / day · Google 15 | More than 15 "triggers throttling"; calculator uses 15 |
| Isolation | One Microsoft 365 tenant per domain, never shared | Not stated for standard tiers |
| Domains | Yours. Bring it free, or we register it in your name for $12 once | Bring your own; one section also offers theirs |
| Setup | 24-48 hours, SPF, DKIM and DMARC verified before handover | "Ready in under 6 hours", DNS configured and verified by hand |
| Refunds | Broken batch reported within 14 days is fixed or refunded | Non-refundable except an unactivated licence within 7 days |
What 100 inboxes costs
Premium Inboxes charges the same per inbox on either platform. A hundred inboxes falls in their Start Up tier at $3.50 each, $350 a month, $4,200 a year. They advertise 20% off annually without publishing the annual figure. Here, 100 Microsoft 365 inboxes on one domain are $30 a month, $360 a year.
On Google the two are close. Our Google inboxes are $3 each at up to 3 on a domain and 15 sends a day; theirs are $3.50 with a calculator that assumes 3 a domain and 15 a day. At the same sending rate, that is $0.20 against $0.23 a month per daily email. The large difference is Microsoft, where we price by the domain rather than by the inbox.
Why our Microsoft price is per domain
Microsoft’s sending ceiling is per tenant, not per mailbox. So we build one tenant per domain, fill it with 100 inboxes, and run each at 3 a day: 300 sends a day for the domain, comfortably inside the tenant ceiling. The cost of a tenant does not grow much with the number of inboxes in it, so pricing per inbox would charge you a hundred times for one tenant. How to provision Microsoft 365 inboxes shows the build.
What Premium Inboxes includes that we do not
Unlimited replacement inboxes. An insured tier at $4.50 an inbox. A client API for creating orders and cancelling inboxes, with white-label for agencies. A dedicated Slack channel. Direct upload to Smartlead and Instantly with warmup switched on. And, by application, an Email Control Centre at $7,500 a month for large senders. If replacements and a Slack channel are worth the difference to you, that is a fair trade to make.
Where Premium Inboxes is the better choice
- You want replacement inboxes on demand and an insured option.
- You run an agency that wants a white-label API.
- You want delivery inside 6 hours.
- You send at volume, where their price falls to $2.80.
Where we are
Microsoft 365 at under a tenth of the per-inbox price, with a tenant per domain stated rather than assumed, and Google slightly cheaper at the same 15 a day. The comparison of platforms is in Microsoft 365 vs Google Workspace for cold email.
What we can show for our own sending: across 11 campaigns on these Microsoft 365 inboxes, 26,698 leads contacted produced a 1.73% bounce rate. Reply rate was 1.9% and ranged from 0% to 4.1% campaign by campaign, because replies depend on the list and the copy, which we do not supply. These are our results, not customer results, and none of it was sent on Google. The full numbers and method are published.
Premium Inboxes alternative: FAQs
How much does Premium Inboxes cost for 100 inboxes?
$350 a month at their published $3.50 per inbox for 1 to 249 inboxes, on Google or Microsoft. Here 100 Microsoft 365 inboxes are $30 a month on one domain, or 100 Google inboxes would be $300 a month across 34 domains.
Do both verify SPF, DKIM and DMARC?
Yes. Premium Inboxes says its engineers configure and verify every record by hand. We verify SPF, DKIM and DMARC before handover and publish free checkers so you can confirm it yourself.
How many emails a day per inbox?
Premium Inboxes says more than 15 a day triggers throttling. We size Google inboxes at 15 campaign sends a day and Microsoft inboxes at 3, with 100 on a domain.
Can I get a refund?
Premium Inboxes says purchases are non-refundable except an unactivated licence within 7 days. Here a broken batch reported within 14 days is fixed or refunded; there are no performance refunds.
Sources
Premium Inboxes’s figures, read on October 26, 2026. Prices on both sides move; ours are on the homepage.
100 Microsoft 365 inboxes on a domain, $30 a month
Or Google at $3 an inbox, up to 3 on a domain. SPF, DKIM and DMARC verified before handover, live in 24 to 48 hours, the domain in your name.
See what you get