Mailforge is the infrastructure side of the "Forge stack" built around Salesforge: Mailforge sells mailboxes on a shared pool of its own sending infrastructure, Infraforge sells private servers with dedicated IPs, and Primeforge sells Google Workspace and Microsoft 365 mailboxes. All three automate DNS (SPF, DKIM, DMARC) and export into any sequencer, and Salesforge bundles warmup via Warmforge.
The surprising fact is structural: this is a sequencer that owns its supply chain across all three Google vs Microsoft vs SMTP. When Google's autumn 2025 suspension wave hit, the Salesforge newsletter was one of the first to document it (21 October 2025) — and used the moment to sell Primeforge's "secure and legitimate" mailboxes.
What it sells
| Product | What it is | Price (Oct 2026, billed yearly) |
|---|---|---|
| Mailforge | Mailboxes on a shared sending pool, "distributing your mailbox accounts among millions of businesses—similar to platforms like Gmail or Outlook" (Mailforge) | $3/mailbox/mo, min 10 |
| Infraforge | Dedicated servers and IPs; "Masterbox" unified inbox | $4/mailbox/mo; $99 per IP per quarter; Masterbox $7/workspace/mo |
| Primeforge | Google Workspace and Microsoft 365 mailboxes, sold for ESP matching | $4.50/mailbox/mo, min 10 |
| Domains | .com registration with DNS automation | $14/yr |
| Add-ons | SSL and domain masking | $2/domain/mo |
Primeforge says its mailboxes are "provisioned directly under Google or Microsoft with full admin access"; the claim is not independently verified.
How it prices
Per mailbox "slot", with a 10-slot minimum and a calculator that sizes domains and slots from emails per sequence, mailboxes per domain (it recommends 2–3) and monthly contacts (Mailforge pricing). Annual billing gives "2 months free"; monthly billing costs more, and there is no free trial. Slots are capacity: "If you purchase 10 slots but only create 5 mailboxes, you are still charged for all 10 slots".
Against the market, Mailforge's $3 shared-pool box costs 1.2 to 6 times as much as Maildoso's $0.49–$2.50 SMTP mailboxes, and Primeforge's $4.50 sits above Google resellers at $2.50–3.50 (Inbox & domain infrastructure).
Mailforge's homepage says "$3 to $2 per mailbox per month", but the pricing page shown to this pass listed only $3. Inboxkit's comparison table lists Primeforge "from $2.88/month" (Inboxkit) against Primeforge's own $4.50. Volume discounts may exist that are not public.
Who uses it and why
Mailforge claims "10k+ businesses" — an unaudited marketing figure. The natural buyer is a Salesforge user, since the stack shares billing and integrates warmup; but all three products export to Instantly, Smartlead and others. Agencies use it to get Google, Microsoft and SMTP from one vendor instead of three.
Where it is strong
- Breadth. Shared SMTP, dedicated IPs and Google/Microsoft from one supplier — no other infra brand reviewed sells all three plus its own sequencer.
- Integrated warmup and placement. Warmforge is bundled free with Salesforge and sells placement tests at $39–169 a month (Warmforge).
- Narrative control. The Salesforge newsletter shapes how the market reads Google's enforcement.
Where it is weak
- Price. Commodity Google resellers undercut Primeforge by $1–2 a mailbox; Maildoso's 1,000-mailbox tier ($0.49) undercuts Mailforge's SMTP by more than 80%.
- Owned by a competitor. An agency on Instantly or Smartlead is buying infrastructure from a rival sequencer.
- Shared-pool exposure. Mailforge's main product inherits the reputation of everyone else on the pool.
- Opacity. No company entity, founder, funding or mailbox count appears on the product sites.
No public data on Mailforge's founding date, legal entity, revenue or mailboxes under management. The corporate relationship to Salesforge is described only as the "Forge stack".
Trajectory
The Forge stack is the template that the larger sequencers followed: Instantly now sells DFY Google accounts and launched its own SMTP network (AirMail) in August 2026 (Instantly); Smartlead resells third-party inboxes. As bundling spreads, Mailforge's standalone appeal outside Salesforge weakens, while its role as Salesforge's margin engine grows.
What this means for an entrant
- Vertical integration is already done by three competitors. Salesforge, Instantly and Smartlead all sell infra; plan to bundle or resell from launch. See Infrastructure strategy: build or partner.
- Three tiers is the right menu. Shared SMTP for cheap volume, dedicated IP for stable senders, Google/Microsoft for top prospects — but resell it before building it.
- Minimum-slot billing is a friction point. Inboxkit and Hypertide advertise "no minimums"; a pay-per-mailbox wallet is the buyer-friendly default.
- Agencies dislike buying infra from a rival sequencer. A neutral sequencer that lets customers pick suppliers (including Mailforge) has a cleaner pitch.