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

What WarmInboxes is

WarmInboxes sells cold email inboxes in two forms. Prewarmed inboxes come on domains the company has already warmed, in packs of three with the domain included, and are ready to send the same day; fresh inboxes go on your own domains and spend two to three weeks in warmup first. Both are offered on Google Workspace and Microsoft 365, with Azure tenants of up to 100 inboxes as a third option, and the terms describe the operator, Upscale Systems LLC, as an authorised reseller of both platforms. The brand also runs Warm Domains, a content site with more than 330 articles and a set of free deliverability tools that funnels readers to the product. The site says it was built by operators sending more than a million cold emails a month, lists Instantly and Smartlead certified partners as endorsers, and quotes customer campaigns with reply rates above 4%; all of that is the company’s own material.

WarmInboxes pricing

The pricing table lives on the offer page rather than the homepage. Prewarmed Google or Microsoft inboxes cost $8 a month each on monthly billing, $7 on two-month and $6 on quarterly, sold in packs of three with a free prewarmed .com or .co domain, so a pack is $24 a month or $18 a month on quarterly billing. Lower-cost prewarmed inboxes on other extensions start at $4.50 through support. A prewarmed Azure tenant of 100 inboxes costs $69 a month, $60 on two-month or $50 on quarterly, which works out at 69 to 50 cents an inbox in your own isolated Microsoft Entra tenant. Fresh Google Workspace inboxes on your own domains cost $3.50 a month with no minimum, $3.25 from 30 inboxes and $3 from 100, or $3.25, $3 and $2.50 on quarterly billing and $3, $2.50 and $2 on yearly. Fresh Microsoft 365 is simpler: $3 monthly, $2.50 quarterly or $2 yearly at any order size. A fresh Azure tenant of 25 to 100 inboxes is $50 a domain a month. Domains cost $12 through WarmInboxes if you do not bring your own.

The terms are the strictest in this directory. All sales are final once a licence is activated or any setup has been done, and the exclusions list change of mind, incompatibility with other tools, unused time and mid-subscription cancellations by name. The only refund is for a licence never activated, set up or allocated, requested within 7 days, reviewed within 24 business hours and paid out in 5 to 10 business days. Prewarmed domains are registered for one year and, by the company’s own account, never renewed, because it believes an old sending history stops helping; if a domain expires while you are sending, a replacement is deployed. Set against that is a deliverability guarantee: follow the sending guidelines and any underperforming inbox is replaced free within 7 days.

Setup and integrations

Create a free account without a card, pick a product, and the prewarmed packs arrive the same day with SPF, DKIM and DMARC already set and admin access to the mailboxes. Fresh orders start a 14 to 21 day warmup that the company’s technicians run before handing over. The offer page says every order includes inbox rotation and deliverability monitoring, and the site names Instantly, Smartlead, EmailBison, ManyReach, Apollo and HubSpot as tools it plugs into, with Cloudflare, Porkbun and GoDaddy for domains you bring. Support runs through WhatsApp around the clock, which the site stresses is staffed by people who run cold email rather than tickets or bots.

Deliverability

The inboxes sit on Google’s, Microsoft’s and Azure’s own infrastructure, which the site describes as US and EU IPs so that one blacklist does not take out a whole pipeline. Prewarmed inboxes carry rules: a minimum 1:2 cold-to-warmup ratio on every inbox, so 15 cold emails need 30 warmup emails, clean verified lists, no link spam and respect for opt-outs. The terms put any reputation damage from breaking those rules on you and say replacements caused that way may be charged, while the guarantee covers inboxes that underperform despite the rules being followed. The one-year life of a prewarmed domain is the structural point to plan around.

Who WarmInboxes is for, and who should look elsewhere

WarmInboxes suits agencies and founders who need to be sending today and will pay a premium for prewarmed inboxes, or who want cheap fresh Google and Microsoft inboxes on yearly billing with the warmup handled. It is a poor fit for anyone who wants a refund option, domains that outlive a year, or a vendor that puts its company name on the homepage. MailDeck sells prewarmed Outlook tenants at $40 and Google plans by the slot, Premium Inboxes sells Google and Microsoft inboxes with volume tiers, and Cheap Inboxes starts at $3.50 with no minimum. The inbox provider comparison scores all of them.

Where PureMail is cheaper, and where WarmInboxes 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. Against WarmInboxes’ fresh Google Workspace inboxes on monthly billing that is cheaper at every size: $33 against $35 for 10, $93 against $97.50 for 30 and $290 against $300 for 100. PureMail also has no all-sales-final clause, no one-year domain expiry and no cold-to-warmup ratio written into its terms. Full details are on the pricing page.

WarmInboxes wins on speed and on committed billing. Nobody else here hands you warmed inboxes with a warmed domain the same day, its fresh Google inboxes fall to $2 on yearly billing at 100 or more, its Microsoft 365 inboxes at $3 monthly undercut PureMail below 101 inboxes, and the Azure tenants at 50 to 69 cents an inbox have no equivalent at PureMail. For an agency that needs replacements dropped in mid-campaign and can live without refunds, it is a serious option. The table below puts the two side by side.