What does a cold email inbox cost?
A cold email inbox costs $2.50 to $4.50 a month at 30 inboxes, on monthly billing, before domains, from the nine sellers here that price by the inbox, read from their own pricing pages and checkouts on 29 October 2026. At 300 inboxes most fall to about $2.81 to $3.25, and Maildoso to $0.75. The same inbox bought straight from Google is $8.40 a user a month on Workspace's flexible plan, so resellers charge 46% to 70% less.
Two sellers sit outside the range because they do not price by the inbox. Inframail charges $147 per billing cycle for what it recommends as up to 400 Microsoft-backed inboxes, which is about $0.40 an inbox at that ceiling. Mailreef charges $249 a month plus $0.001 a send for its own servers, which only gets cheap past about 100 inboxes.
The headline numbers are the least reliable part of these pages. Four of the twelve bill on a cycle shorter than a calendar month, three lead with an annual rate, and the cheapest figure on Litemail's homepage cannot be bought on any plan it lists.
What a cold email inbox provider sells
An inbox provider sells mailboxes on domains you are not sending your normal company mail from, set up so a sequencer such as Instantly or Smartlead can send through them. The point is to spread volume: a few dozen cold emails a day from each of many inboxes, so no single address or domain carries enough volume to look like bulk mail.
What is in the box varies more than the word 'inbox' suggests. There are three kinds, and the sellers in this census sell one, two or all three.
Google Workspace and Microsoft 365 seats
Real Google or Microsoft accounts, bought by the seller and set up on your domains. InboxKit, Zapmail, Premium Inboxes, Puzzle Inbox, Litemail and Primeforge sell these. They send from Google's or Microsoft's own servers, which is the reason people pay for them, and they inherit Google's and Microsoft's sending caps and terms, which is the risk.
The seller's own mail servers
Mailboxes on infrastructure the seller runs: Mailforge (shared IP addresses), Infraforge (dedicated IP addresses), Maildoso (its own servers with IP rotation) and Mailreef (dedicated servers). Cheaper per inbox, no Google or Microsoft terms in the way, and the reputation of the sending IP is the seller's, not Google's.
Microsoft-backed bulk plans
Inframail describes its product as Microsoft-backed and built on Microsoft's cloud, sold as a flat plan with a recommended inbox ceiling rather than per seat. Its page does not say whether each inbox is a licensed Microsoft 365 seat, and it also advertises a dedicated US IP address, which is not how Exchange Online normally assigns sending addresses.
If the question is Google Workspace or Microsoft 365, the sellers mostly answer it for you by charging the same for both: InboxKit's FAQ says there is 'no Microsoft premium', and Litemail and Zapmail list one price for either. Puzzle Inbox is the exception, at $35 for 100 Outlook inboxes against $3 each for Google, and it tells buyers on its own pricing page that it does not recommend Outlook right now.
Twelve inbox providers and what they charge
Prices are the monthly-billing rate per inbox in US dollars, as each seller shows it, read 29 October 2026. 'Cycle' is how often the seller actually invoices, from its checkout or terms. Domains are excluded everywhere; the domain column says what the seller charges for them.
| Provider | Inbox type | Per inbox, monthly billing | Minimum | Billing cycle | Domains | Refunds |
|---|---|---|---|---|---|---|
| InboxKit | Google, Microsoft | $3.00 ($2.50 billed yearly) | 1 inbox | Monthly, from a prepaid wallet | Not priced on the page | Wallet top-ups non-refundable; balance forfeited on closing |
| Zapmail | Google, Microsoft | $3.90 / $3.30 / $2.99 by plan | $39 (10 inboxes) | Monthly | Shown at checkout only | Non-refundable |
| Premium Inboxes | Google, Microsoft | $3.50 (1 to 249), $3.00 (250 to 1,249) | 1 at checkout | Every 4 weeks at checkout | Contradictory: included, and bring your own | All sales final |
| Puzzle Inbox | Google, Microsoft | $3.00 Google; $35 per 100 Outlook | 15 Google inboxes ($45) | Every 29 days | Bring your own, or theirs on warmed plans | Within 24 hours, before onboarding |
| Litemail | Google, Microsoft | $3.70 / $3.23 / $2.97 / $2.83 by plan | $37 (10 inboxes) | Monthly | $15 a year | Non-refundable |
| Primeforge | Google, Microsoft | $4.50 falling to $3.50 | 10 slots ($45) | Monthly | Connect your own free | No refunds of prepaid fees |
| Mailforge | Own servers, shared IP | $3.00 falling to $2.00 | 10 slots ($30) | Monthly | .com $14 a year | No refunds of prepaid fees |
| Infraforge | Own servers, dedicated IP | $4.00 falling to $3.00 (quarterly) | 10 slots ($120 a quarter) | Quarterly or yearly only | .com $14 a year | No refunds of prepaid fees |
| Maildoso | Own servers | $2.50 (30), $0.75 (300), $0.49 (1,000) | $75 (30 inboxes) | Monthly | $15 a year | Only after 3 days of outage on its side |
| Mailreef | Own dedicated servers | $249 a month + $0.001 a send | $249 | Monthly (or $240 on 12 months) | Not priced | Not refundable under any circumstances |
| Inframail | Microsoft-backed | $147 for up to 400; $387 for up to 1,000 | $147 | Every 28 days | Not priced; $5 to bring one | 30-day guarantee on hosting only |
| Mailscale | Not stated | Not published | Not published | Not published | Included | None for lack of results |
Mailscale is in the table because it ranks and is named in every comparison, but its site now sells an 'agentic' service, sends previous customers to a login page, has no pricing page, and answers 'How much does it cost?' with a call booking. There is nothing to price.
What 'per month' means on four of these pages
Inframail's homepage says '$147 /Month'. Section 3 of its terms says billing cycles are 'monthly (every 28 days, equaling 13 invoices per year)'. Premium Inboxes' checkout reads '$3.50 × 249 /4 weeks' with the next charge 28 days out, while its own terms say 'paid in advance on a monthly basis'. Puzzle Inbox's terms open with 'Billing periods renew every 29 days.' Infraforge has no monthly billing at all: quarterly or yearly.
| Provider | Price as shown | Invoices a year | Real cost a year | Per calendar month | Above the shown price |
|---|---|---|---|---|---|
| Inframail Unlimited | $147 a 'month' | 13 | $1,911 | $159.25 | 8.3% |
| Inframail Agency | $387 a 'month' | 13 | $5,031 | $419.25 | 8.3% |
| Premium Inboxes | $3.50 an inbox | 13 | $45.50 an inbox | $3.79 | 8.3% |
| Puzzle Inbox | $3.00 an inbox | 12.59 | $37.76 an inbox | $3.15 | 4.9% |
| Infraforge | $12 a slot a quarter | 4 | $48 a slot | $4.00 | 0% (but 3 months up front) |
| Everyone else | Per month | 12 | 12 × the price | The price | 0% |
The 28-day cycle also changes what a discount means. Inframail's yearly toggle says 'Save 30%' and shows $111.47 a month billed yearly, or $1,337.64. Against 13 invoices of $147 that is exactly 30.0% less. Against the 12 × $147 = $1,764 a reader multiplies in their head, it is 24.2%. The page never says which.
The monthly bill at 10, 30, 100 and 300 inboxes
Each seller's own rate card applied to four common sizes, on monthly billing and a calendar month, excluding domains. Where a seller sells plans plus extra inboxes, the cheapest combination is used. Computed from published rates, not invoices.
| Provider | 10 inboxes | 30 inboxes | 100 inboxes | 300 inboxes | Per inbox at 300 |
|---|---|---|---|---|---|
| Mailforge | $30.00 | $90.00 | $300.00 | $842.00 | $2.81 |
| Litemail | $37.00 | $97.00 | $297.00 | $849.00 | $2.83 |
| Zapmail | $39.00 | $99.00 | $299.00 | $899.00 | $3.00 |
| InboxKit | $30.00 | $90.00 | $300.00 | $900.00 | $3.00 |
| Puzzle Inbox (Google) | $47.20 (15 minimum) | $94.40 | $314.66 | $943.97 | $3.15 |
| Premium Inboxes | $37.92 | $113.75 | $379.17 | $975.00 | $3.25 |
| Infraforge | $40.00 | $120.00 | $400.00 | Tiered, not published per step | $3.00 to $4.00 |
| Primeforge | $45.00 | $135.00 | $450.00 | $1,292.00 | $4.31 |
| Maildoso | Sold in 30s | $75.00 | Buy 300: $225 | $225.00 | $0.75 |
| Mailreef (25 sends a day) | $254.00 | $264.00 | $299.00 | $399.00 | $1.33 |
| Inframail | $159.25 | $159.25 | $159.25 | $159.25 | $0.53 |
| Google Workspace direct | $84.00 | $252.00 | $840.00 | $2,520.00 | $8.40 |
Three things decide the order more than the headline rate. Volume breaks arrive late: the Forge products (Mailforge, Infraforge, Primeforge) charge the first 10 slots at the top rate and step down only every 100 slots after that, so nothing changes until 111. Flat plans win only near their ceiling: Inframail's $159.25 is the most expensive option at 10 inboxes and the cheapest at 300. And the two own-server plans with per-send or bulk pricing, Maildoso and Mailreef, are the cheapest at scale and among the dearest at 10.
Domains add a predictable amount. At three inboxes a domain, which Premium Inboxes and Puzzle Inbox both specify, 30 inboxes need 10 domains: $140 to $150 a year at Mailforge's $14 or Litemail's and Maildoso's $15, or about $12 a month on top of every figure in the table.
Price cliffs worth knowing before you order
Premium Inboxes applies the tier price to every inbox, so the tier break is a cliff. At its checkout, 249 inboxes cost $871.50 and 250 cost $750.00. Every order from 215 to 249 costs more than 250 would (215 × $3.50 = $752.50).
Zapmail's plans cross over twice: Starter plus extra inboxes passes the $99 Growth plan at 28 inboxes ($102), and Growth plus extras passes the $299 Pro plan at 92 ($300.50). Its yearly toggle is badged '2 months free'; the plan fees match that, but Starter's extra inboxes stay at $3.25 instead of the $2.92 it would imply.
Cost per 1,000 cold emails at each seller's own sending limit
An inbox is only as cheap as the email it is allowed to send. Most sellers publish a daily limit per inbox, and some enforce it in their terms. At 30 inboxes and 22 sending days a month:
| Provider | Cold sends per inbox per day (seller's figure) | Cold emails a month | Monthly cost | Per 1,000 emails |
|---|---|---|---|---|
| Mailforge | 30 recommended, 100 maximum | 19,800 | $90.00 | $4.55 |
| Infraforge | 30 recommended | 19,800 | $120.00 | $6.06 |
| Primeforge | 30 recommended | 19,800 | $135.00 | $6.82 |
| Litemail | 20 (calculator default) | 13,200 | $97.00 | $7.35 |
| Maildoso | 15 (terms: ramp from 1 to 15) | 9,900 | $75.00 | $7.58 |
| Premium Inboxes | 15 | 9,900 | $113.75 | $11.49 |
| Puzzle Inbox (Google) | 12, enforced by its terms | 7,920 | $94.40 | $11.92 |
| Google Workspace direct | 30 (practitioner norm) | 19,800 | $252.00 | $12.73 |
| Mailreef | 25 (calculator) | 16,500 | $265.50 | $16.09 |
InboxKit and Zapmail publish no daily figure, so they cannot go in this table, and Inframail's slider assumes about 10 a day per inbox, which at its 400-inbox ceiling and 80,000 cold emails a month works out near $1.99 per 1,000. Puzzle Inbox's limit is the one with teeth: its terms cap Google inboxes at 12 cold and 12 warm-up emails a day and Outlook at 3 and 3, and say it may suspend or terminate, without refund, any account that exceeds them.
The caps Google and Microsoft put on every inbox
The six sellers of Google and Microsoft seats are selling accounts that live under Google's and Microsoft's rules, and those rules are written down. None of the pages ranking for this query sets them side by side.
- Google Workspace: 2,000 messages a day per user, 3,000 external recipients a day, and 500 a day on trial accounts. Trial limits lift only after the domain has cumulatively paid $100, and 'it can take up to 75 days' after that. Users that send spam 'might be permanently restricted from sending email'.
- Microsoft Exchange Online: 10,000 recipients a day per mailbox and 30 messages a minute. Since 2025 a tenant-wide external limit applies as well: 500 × (licences^0.7) + 9,500 a day, so 14,906 for a 30-licence tenant.
- New Microsoft tenants get a fraction of that: 10% of the quota in the first 30 days and 25% in days 31 to 60. A 30-inbox tenant less than a month old can reach about 1,490 external recipients a day in total, roughly 50 an inbox.
- Microsoft trial tenants: Microsoft's own two pages disagree. The Exchange Online limits page says 5,000 external recipients a day; the tenant-limits announcement says 500.
Microsoft's announcement of the tenant limit also says, in so many words, that Exchange Online 'doesn't support bulk or high-volume email'. Google's acceptable use policy for Workspace prohibits unsolicited mass email and prohibits reselling end user accounts as part of a commercial product offered to third parties. A buyer of reseller seats should read both before reading any seller's guarantee, because the seller's terms say what happens when Google or Microsoft acts: Puzzle Inbox's give no refund, credit or compensation for Google or Microsoft suspensions or domain seizures, and state that Google's and Microsoft's terms supersede its own.
The rules on the receiving side
Splitting volume across inboxes exists because of receiver rules. Since February 2024 Google requires anyone sending more than 5,000 messages a day to Gmail accounts to authenticate with SPF and DKIM, publish DMARC, offer one-click unsubscribe on marketing mail, and keep the spam rate in Postmaster Tools under 0.10%, never reaching 0.30%. Google's FAQ says enforcement ramped up from November 2025, including permanent rejections.
Yahoo applies the same authentication rules, asks for a spam rate under 0.3%, wants unsubscribes honoured within 2 days, and declines to state a volume threshold. Microsoft applied similar rules to Outlook.com, Hotmail and Live addresses for domains sending over 5,000 emails a day from May 2025, as Petri reported at the time.
None of this is avoided by having many inboxes: authentication is per domain and spam complaints are per recipient. The inbox count controls how much each address sends; it does nothing for content people mark as spam. One practitioner on Hacker News described the whole routine (many lookalike domains, a few mailboxes each, two weeks of warm-up) as 'learning to be a spammer', which is a fair description of what receivers are built to detect.
What the terms say that the pricing pages do not
Every seller here sells a monthly product and nearly every one makes it hard to get money back. The clauses that matter in month three:
- Maildoso shows a '30-days money-back guarantee' badge. Its terms refund only if mailboxes 'fail to send emails for 3 or more consecutive days due to a fault on Maildoso's side', deduct $15 a domain from any refund, and say Maildoso 'does not provide a mailbox warm-up service'.
- InboxKit bills from a prepaid wallet. Its refund policy: 'If you close your account, any remaining wallet balance is forfeited.'
- Zapmail says on its pricing page that Google Workspace mailbox pricing 'increases after the first year' and does not show the new price. Its terms let it change pricing and renewal rates 'at any time'.
- Puzzle Inbox takes cancellations only by WhatsApp, with 5 days' notice, deletes inboxes 48 hours before the renewal date, and keeps the domains on its warmed plans: 'All warmed inbox domains remain the exclusive property of Puzzle Inbox.'
- Mailforge, Infraforge and Primeforge (one company, Salesforge) say 'cancel your subscription anytime' in the pricing FAQ; the terms say cancellations 'must be filed 7 days before the end of the term', through live chat.
- Litemail deprovisions all mailboxes and domains on cancellation and treats every purchase as final.
- Mailreef: payments 'shall not be refundable under any circumstances', and it may terminate 'at any time, without notice, for any reason'.
The practical consequence is about domains, not inboxes. If your sending domains are registered by the seller and the seller deletes or keeps them when you leave, you lose the warm-up and reputation you paid for and start again elsewhere. Register domains yourself where the seller allows it (Zapmail, Puzzle Inbox's standard plans, the Forge products, Maildoso and Inframail all accept your own) and switching costs drop to the setup time.
Reseller or straight from Google and Microsoft?
Buying direct costs $8.40 a user a month on Google Workspace Business Starter's flexible plan, per Google's own billing help page. Microsoft's Business Basic page lists $7.00 a user a month paid yearly or $8.40 on a monthly subscription, and Exchange Online Plan 1 at $4.00 paid yearly. At 30 inboxes, Google direct is $252 a month against $90 to $135 from the resellers selling the same Google seats.
What the extra $117 to $162 a month buys is a direct contract with Google: no reseller between you and the account, no question of whether reselling seats breaks Google's acceptable use policy, and admin access by default, which Puzzle Inbox grants only 'at its sole discretion'. What it costs, besides money, is setup time (DNS, authentication, sequencer connection) and Google's trial-account limit of 500 messages a day until $100 has been paid on the domain.
Pick by the condition that applies to you
- Under 30 inboxes, want Google seats, monthly: InboxKit at $3.00 with no minimum, or Zapmail's $39 Starter. Check InboxKit's wallet terms before topping up more than a month.
- Under 30 inboxes, cheapest possible: Mailforge at $3.00 on shared IPs, or Maildoso's $75 for 30 on its own servers if 15 sends a day is enough.
- 100 to 400 inboxes: Inframail's flat plan undercuts everything per inbox, provided you accept a 28-day cycle and an unanswered question about what kind of Microsoft inbox you are getting.
- 300 or more on your own servers: Maildoso ($225 for 300) or Mailreef ($249 plus sends), both with no refunds in practice.
- You need to keep your domains: avoid Puzzle Inbox's warmed plans and any plan where the seller registers the domains, and register them yourself.
- You want no reseller in the chain: Google direct at $8.40, or Microsoft Business Basic, with the setup work and the trial limit.
How to check an inbox provider's price yourself
- Click the billing toggle. InboxKit's page defaults to annual ($2.50); monthly is $3.00. Primeforge's homepage range, '$4.5 to $3.5', is the monthly range; yearly billing goes to $2.92.
- Go to checkout without paying. Premium Inboxes' four-week cycle and Puzzle Inbox's 29-day cycle appear there, and Puzzle Inbox's 15-inbox minimum is the point where the quantity button stops.
- Search the terms for 'days', 'refund', 'domain' and 'cancel'. Inframail's 13 invoices a year and Maildoso's 3-day refund condition are both one search away.
- Ask who owns the domains when you leave, in writing, before you buy. Only Zapmail states plainly that you own domains bought through it.
- Multiply the per-inbox price by your seller's own daily sending limit before comparing sellers, using the table above.
Headline prices that are not on the price list
Litemail's homepage says 'Starts at $2.5/inbox'. Its cheapest published per-inbox rate, on the 300-inbox Scale plan, is $2.83, and its cheapest extra inbox is $2.85. Its own testimonials quote '$2.99/month for 200 accounts' and '$3.99/month for 10 accounts', neither of which matches the current table.
Maildoso's pricing page shows $499 for 1,000 inboxes; its checkout charged $500.00, and the page's own structured data says $0.50 an inbox where the visible FAQ says $0.49. The 1,000-inbox link carries a promotion code on a page that also says 'we do not run promotions or sales'. These are small sums, but a buyer who budgets from the headline is budgeting from a number the checkout does not charge.
Who writes the pages that rank for this
The top four results for 'cold email inbox providers' on 29 October 2026 were Primeforge, InboxKit, Infraforge and Salesforge. Three of those four belong to one company. On 'zapmail vs inboxkit', seven of eight results were written by one of the two vendors or a competitor; on 'mailreef vs maildoso vs inframail', eight of nine. Every seller in this census publishes 'alternatives' pages about the others.
That does not make their prices wrong; most of what they say about themselves checks out. It does mean that the pages comparing them are each written by one of the things being compared, and that the clauses above, which every seller has about itself, appear on none of them.
What this page does not know
This page does not know which seller's inboxes land in the inbox most often. That needs the same message sent from each seller's inboxes, on fresh domains warmed the same way, to the same seed list on Gmail, Outlook and Yahoo, over several weeks. No seller in this census publishes such a test, every placement figure on their sites is their own, and this page has not run one. Until someone does, treat any seller's 'inbox placement rate' as marketing and run a seed test on a handful of inboxes before ordering hundreds.
It also does not know how often reseller Google and Microsoft seats are suspended, what Zapmail charges for Google mailboxes in year two, any seller's standard domain price where it is shown only at checkout, whether Mailreef's $0.001 a send also bills warm-up sends, or what kind of Microsoft inbox Inframail provisions. Practitioner reports on these sellers by name are close to absent from public forums, so there is no independent record of any of them over time. Ask each of those questions in writing before you buy, and keep the answer.
Which cold email inbox provider is cheapest?
At 30 inboxes on monthly billing, Maildoso is cheapest at $75 a month for its own servers, then Mailforge and InboxKit at $90. At 300, Inframail's $159.25 a calendar month and Maildoso's $225 are a third of everyone else. For Google seats bought monthly, InboxKit's $3.00 with no minimum is the simplest low price.
The cheapest provider is rarely the deciding factor, because the gap between the cheapest and dearest per-inbox seller at 30 inboxes is $60 a month. Decide on the things that cost more than $60 when they go wrong: whether you own your domains, what the billing cycle really is, and what the terms give back when Google or Microsoft shuts an inbox. Then take the cheapest seller that passes those three.