Mailforge

Inbox infraUpdated Oct 27, 2026

Cold email mailboxes sold by the slot on a shared IP, one mail-sending address other businesses use at the same time, priced per mailbox per month. Pick Mailforge for 10 or more mailboxes sent to company domains. Pick InboxKit under 10.

The verdict

Mailforge sells cold email mailboxes by the slot, the paid capacity to hold one mailbox whether it is filled or not, with a minimum purchase of 10 slots. Every mailbox sits on a shared IP, the same way a free Gmail or Outlook account shares a server. A 25-mailbox example on Mailforge’s own calculator costs $75 a month billed monthly, or $60 a month billed yearly. Domains cost $14 a year per .com domain, billed yearly. Infraforge, the sibling product, swaps the shared IP for a dedicated IP, a mail-sending address only one sender uses. The same 25-mailbox example costs $100 a month billed quarterly, or $83 a month billed yearly, and bundles access to Infraforge’s own API, the way your code talks to the tool, into the base price. The math: InboxKit charges a flat $3.00 a mailbox a month billed monthly, or $2.50 a mailbox a month billed yearly, with no minimum purchase. At 25 mailboxes, 25 × $3.00 = $75 a month billed monthly, which ties Mailforge’s rate for the same count, but InboxKit charges nothing extra for buying fewer than 10 mailboxes, where Mailforge still bills for a full 10 slots.

Premium Inboxes drops its per-inbox rate at larger counts, but it bills every 4 weeks, 13 times a year. At 1,250 mailboxes, its Enterprise tier runs 1,250 × $2.80 = $3,500 every 4 weeks, so $3,500 × 13 = $45,500 a year. InboxKit runs 1,250 × $3.00 × 12 = $45,000 a year billed monthly, or 1,250 × $2.50 × 12 = $37,500 a year billed yearly. At 1,250 mailboxes, InboxKit costs less on either basis. Pick InboxKit under 10 mailboxes, or wherever a flat no-tier rate weighs more than a volume discount. Pick Premium Inboxes once volume runs into the hundreds, since it sets up domains and inboxes for the buyer at that scale, not because it beats Mailforge or InboxKit on price. Pick Infraforge over Mailforge when a dedicated IP and bundled API access weigh more than the lower price.

What users say

“I saw a guy setting up cold email infrastructure today. No maildeck. No infraforge. No mailforge. He just sat there configuring spf, dkim, and dmarc records by hand. Like a psychopath.”
X

Best for

Teams sending cold email to company domains that want SPF, DKIM and DMARC, the records that prove mail is real, set up automatically, and are fine buying at least 10 mailbox slots at once.

Not for

Skip it if the list is personal email addresses instead of company domains, since shared-IP pricing like Mailforge’s is built around company mail. Skip it under 10 mailboxes too, since InboxKit charges for only what is used with no minimum.

Pricing truth

$3 a mailbox a month billed monthly, set by a calculator with no fixed plan names. At 25 mailboxes that comes to $75 a month billed monthly, or $60 a month billed yearly. Mailbox slots sell in blocks of 10 at minimum, so a 5-mailbox order still bills for 10 slots. Domains cost $14 a year per .com domain, billed yearly, with no discount the way mailboxes get one on a yearly plan. SSL and domain masking, an add-on that hides the domain actually sending the mail, costs $2 a domain a month. A two-session consulting add-on, Forge Expert Double Session, costs $500 one time for two sessions. There is no free trial, since Mailforge’s own FAQ says a domain and a mailbox slot have to be bought before the app does anything. Infraforge runs the identical calculator on dedicated IPs instead of shared ones. The same 25-mailbox example prices mailboxes at $4 a mailbox a month billed quarterly, for $100 a month billed quarterly or $83 a month billed yearly, with access to Infraforge’s own API included at no extra cost. Infraforge adds two add-ons Mailforge does not carry: IP addresses at $99 an IP a month billed quarterly, and Masterbox, a dashboard that shows every mailbox across a workspace at once, at $7 a workspace a month billed yearly or $9 a workspace a month billed quarterly. Both products give 2 months free on yearly mailbox billing, and neither discounts domains. The math: Infraforge’s $4 a mailbox a month billed quarterly is a third higher than Mailforge’s $3 a mailbox a month billed monthly. On the shared 25-mailbox example, 25 × $4 = $100 a month billed quarterly against Mailforge’s 25 × $3 = $75 a month billed monthly, a $25 a month gap that buys a dedicated IP and bundled API access instead of a shared one.

When we use it

Automate SPF, DKIM and DMARC instead of typing them in by hand for every domain.
Buy mailbox slots in blocks of 10 or more on a shared IP.
Move to Infraforge for a dedicated IP, plus bundled API access.
Skip it when the list is personal email addresses instead of company domains, since shared-IP pricing is built around company mail.

How to wire it

Count the mailboxes needed this month, then round up to the next 10, since Mailforge sells mailbox slots in blocks of 10 at minimum.
Pick Mailforge for a shared IP, or Infraforge for a dedicated IP.
Let the automated setup handle SPF, DKIM and DMARC instead of entering them by hand.
Check InboxKit’s flat $3.00 a mailbox a month billed monthly, or $2.50 a mailbox a month billed yearly, before buying under 10 mailboxes on Mailforge.
Move to Premium Inboxes once volume runs into the hundreds, where it sets up domains and inboxes for the buyer instead of leaving that work to be done by hand.

Margin notes

Below 10 mailboxes, InboxKit’s no-minimum pricing beats Mailforge outright, since Mailforge still bills for a full 10 slots regardless of the number of mailboxes actually created.
Zapmail’s Starter plan costs $39 a month billed monthly for 10 mailboxes, and ScaledMail charges $3.50 a mailbox a month billed monthly for Google Workspace mailboxes, two more mailbox sellers worth pricing against Mailforge.
Mailforge and Infraforge both skip the free trial. Their own FAQ says a domain and a mailbox slot have to be bought before the app does anything.
A Mailforge subscriber on X canceled after sending to a list of personal email addresses instead of company domains. Shared-IP pricing like Mailforge’s is built around sending to company mail.

Common questions

What’s the difference between Mailforge and Infraforge?▾

Mailforge runs on a shared IP at $3 a mailbox a month billed monthly for a 25-mailbox example. Infraforge runs on a dedicated IP at $4 a mailbox a month billed quarterly for the same count, and bundles API access into the price.

How much does a cold email mailbox cost on Mailforge?▾

A 25-mailbox example costs $75 a month billed monthly, or $60 a month billed yearly. Mailboxes sell in blocks of 10 slots at minimum, so a smaller order still bills for 10.

Is InboxKit cheaper than Premium Inboxes?▾

At 1,250 mailboxes, yes. Premium Inboxes’ Enterprise tier runs $3,500 every 4 weeks, 13 times a year, so $45,500 a year. InboxKit’s flat rate of $3.00 a mailbox a month billed monthly comes to $45,000 a year, and $2.50 a mailbox a month billed yearly comes to $37,500 a year billed yearly.

Do Mailforge and Infraforge include DNS setup?▾

Yes. Both automatically set SPF, DKIM and DMARC on every domain, included in the base mailbox price.

What’s the minimum number of mailboxes to buy?▾

Mailforge and Infraforge both sell a minimum of 10 mailbox slots. InboxKit has no minimum at all, so a single mailbox costs $3.00 a month billed monthly.

What to do next

Pick Mailforge when the list is company domains and a shared IP is an acceptable trade for a lower rate. Pick Infraforge instead when a dedicated IP and bundled API access weigh more than the price gap. Under 10 mailboxes, or wherever a flat no-minimum rate weighs more than a volume discount, InboxKit is the simpler buy. Try InboxKit For hundreds of inboxes, Start with Premium Inboxes.