ColdInfra review (2026): pricing, pros and cons, alternatives

What ColdInfra is

ColdInfra is a done-for-you setup service for cold email mailboxes on Google Workspace and Microsoft 365. You buy the domains, point their nameservers at ColdInfra, and it writes and verifies SPF, DKIM, DMARC and MX, provisions the mailboxes, sets up forwarding and a tracking domain, and hands you credentials formatted for your sequencer. The pitch is ownership and transparency: domains stay in your name, DNS access is scoped and revocable, and every change is logged with a timestamp. The site claims a 98.7% inbox rate and more than 14,000 mailboxes live, which are its own figures. The company behind the brand is not named anywhere on the site; the terms are governed by the law of England and Wales and support runs through an email address and a booked call.

ColdInfra pricing

Three tiers, each a monthly rate per mailbox plus a setup fee paid once: Starter at $3 a mailbox from 10 mailboxes with a $24.99 fee, Growth at $2.80 from 30 with a $40 fee, and Scale at $2.50 from 100 with a $54.99 fee. The pricing page shows identical rates on its Google Workspace and Microsoft 365 tabs and the FAQ says both start at $2.50, but the about page says Microsoft starts at $3, so confirm before you order a Microsoft fleet. The configurator does the arithmetic: 30 mailboxes come to $84 a month plus the $40 fee, so $124 on day one and $84 a month after, across 15 sending domains rated at 18,000 emails a month in total. Domains are not included; you buy them at your registrar. Plans are rated at 20 emails a day per mailbox, which the acceptable use policy calls the safe steady state rather than a target.

Billing runs monthly through Stripe and you can cancel at any time. Every plan carries a 30-day refund: email support within 30 days of the service starting with what did not work, get a decision within five business days, and the month’s subscription fee comes back. The setup fee stays, because the work it pays for has been delivered.

Setup and integrations

Pay, sign in with an emailed code, add each domain and paste the two nameservers at your registrar. From the moment the nameservers point at ColdInfra, the records are published and the mailboxes provisioned inside 24 hours, with most domains live the same day and propagation taking up to 48 hours at the outside. The dashboard shows each domain as pending, verifying or live, logs every DNS record touched, monitors hourly, and presents credentials ready to paste into Instantly, Smartlead, Lemlist, Email Bison, ReachInbox or any sequencer that accepts SMTP or Google and Microsoft logins. Warm-up is where the site disagrees with itself: the homepage and pricing page say warm-up runs for two to three weeks before you send, while the about page says ColdInfra does not run warm-up as a managed service and instead sets the warm-up inside your sequencer to a safe ramp. Plan on the second version. A reused domain is reputation-checked first, and the company will recommend a fresh one over warming a liability.

Deliverability

These are official Google and Microsoft accounts, so the sending reputation starts where those providers put it, and ColdInfra’s contribution is the configuration around them: SPF under the lookup limit, DKIM enabled, DMARC published, MX and forwarding so replies land in one place, a custom tracking domain, and hourly monitoring. The 20-a-day rating per mailbox and the three-to-four-mailboxes-per-domain ratio are conservative by design. If a provider suspends a domain, ColdInfra moves it to the other provider or replaces it, since it cannot go back to the provider that suspended it, and the acceptable use policy bars purchased or scraped lists and overriding the warm-up ramp.

Who ColdInfra is for, and who should look elsewhere

ColdInfra suits agencies and teams that want official Google or Microsoft inboxes at a low monthly rate, own their domains and are happy to pay a setup fee once. It is a poor fit for teams that need to be sending within hours, want warm-up unambiguously handled for them, or dislike paying before they have seen a single inbox. InboxKit sells the same account types at $3 flat with no setup fee, Cheap Inboxes starts at $3.50 with no minimum, and Mailpool adds its own SMTP inboxes and dedicated IPs. The inbox provider comparison scores all of them.

Where PureMail is cheaper, and where ColdInfra wins

PureMail’s Google Workspace and Microsoft 365 inboxes, configured and connected by a team cost $3.30 each for 10, $3.10 for 30 to 100 and $2.90 for 101 or more, billed monthly with no setup fee, one price for both providers, and the inboxes live in about 4 hours. Because ColdInfra charges a setup fee, PureMail is cheaper in the first month at small sizes: $33 against $54.99 for 10 mailboxes and $93 against $124 for 30. PureMail also needs no nameserver change at your registrar and no two-to-three-week ramp before sending at full volume. Full details are on the pricing page.

ColdInfra wins on the running rate. At $3, $2.80 and $2.50 a mailbox it is below PureMail at every tier, and over a full year it comes out ahead by about $11 at 10 mailboxes, $68 at 30 and $665 at 100, with a 30-day refund on the subscription, ownership guarantees written into the terms, a tracking domain and hourly monitoring in the price. For an agency that owns its domains and plans to keep the fleet for a year, it is the cheaper official-account option. The table below puts the two side by side.