# Mailforge

> Mailforge is cold email mailbox infrastructure, not a sending platform: it registers domains, provisions mailboxes on them in bulk, configures SPF, DKIM, and DMARC automatically, and hands you credentials to connect into a sequencer such as Instantly, Smartlead, or Salesforge, priced at about $3 per mailbox slot per month on annual billing with a ten-slot minimum and $14 per year for .com domains.

- Category: Cold Email Outreach (https://saastracker.org/categories/cold-email-outreach)
- Website: https://www.mailforge.ai
- Starting price: $3 per mailbox slot per month billed yearly, ten-slot minimum, so about $30 per month
- Free plan: No
- Free trial: None; this is provisioned infrastructure with real domain and hosting costs behind it
- Founded: 2022, HQ: Tallinn, Estonia, Ownership: Founder-led, largely bootstrapped with a small early round
- Profile last reviewed: 2026-08-22
- Canonical profile: https://saastracker.org/products/mailforge

## Overview

It is worth being blunt about what Mailforge is, because the category confuses people constantly. Mailforge does not send your campaigns. It does not build sequences, manage replies, or report on open rates. It is the layer underneath: the domains you send from, the mailboxes on those domains, and the DNS records that make those mailboxes look legitimate to Google and Microsoft. You buy it alongside a sending platform, not instead of one. A small business running outbound typically ends up with two bills, one for the sequencer and one for the infrastructure, and Mailforge is a candidate for the second.

The problem it solves is real and extremely tedious. Running cold email safely means spreading volume across many mailboxes on many secondary domains, so that no single domain carries enough reputation risk to matter and your primary company domain never touches outbound at all. Doing that by hand means registering twenty domains, waiting on nameserver propagation, creating mailboxes, writing SPF records, generating DKIM keys, publishing DMARC policies, and then repeating the whole ritual every time you scale. Mailforge automates that into a calculator and a checkout.

The pricing model is slot-based rather than mailbox-based, which is a small but useful distinction: you buy capacity, and you can create, delete, and recreate mailboxes inside that capacity without new charges. The published rate is $3 per slot per month billed yearly or $5 per slot billed monthly, with a minimum of ten slots, so the realistic entry point is $30 to $50 a month plus $14 a year per .com domain. An SSL and domain masking add-on costs $2 a month or $6 a year.

Mailforge is one of six products in the Forge Stack built by Salesforge, the Tallinn-based company founded by Frank Sondors in 2022. The siblings matter for choosing correctly: Mailforge is the shared, cheaper infrastructure tier, Primeforge sells real Google Workspace and Microsoft 365 mailboxes at a higher price, Infraforge sells private dedicated infrastructure, and Warmforge handles warm-up. That means Mailforge is a deliberate budget position within a ladder, and the honest question when buying it is whether shared infrastructure is good enough for what you are sending.

## How it works

1. You start with the calculator on the pricing page: enter how many emails per sequence you send, how many mailboxes you want per domain, and how many contacts you touch per month, and it tells you how many domains and mailbox slots you need. This is the part most first-time buyers get wrong on their own, usually by putting far too many mailboxes on one domain.

2. You buy domains through Mailforge (about $14 a year for a .com) or connect domains you already own. Mailforge then takes over DNS configuration: nameservers, MX, SPF, DKIM, and DMARC are written automatically rather than pasted by hand into a registrar panel at midnight.

3. You provision mailboxes into your purchased slots, typically a handful per domain, with naming conventions that can be generated in bulk rather than typed one at a time. Slots are capacity, so deleting a mailbox frees the slot for a new one at no extra cost.

4. You export the credentials or connect directly into your sending platform. Mailforge is designed to feed Salesforge, Instantly, Smartlead, and other sequencers, and the mailboxes appear there as ordinary connected sending accounts.

5. You then warm the mailboxes before sending real volume, using Warmforge or whatever warm-up your sending platform includes, and ramp gradually. Mailforge provisions healthy infrastructure; it does not make a brand-new domain instantly safe to blast from, and no vendor honestly can.

## Best for

Small businesses and agencies that have chosen a sending platform and now need ten to a few hundred secondary mailboxes on properly configured domains, without spending a weekend in a registrar's DNS panel or risking their primary company domain.

## Not the right fit for

- Anyone looking for a sending platform; Mailforge has no sequences, no unified inbox, and no campaign reporting, and buying it alone gets you mailboxes and nothing to send from them.
- Businesses sending from a single company mailbox at low volume; ten slots minimum is more infrastructure than you need and you should just use your existing Google Workspace account.
- Buyers who require genuine Google Workspace or Microsoft 365 mailboxes for maximum inbox placement, which is what the more expensive sibling Primeforge exists to sell.
- Teams that want fully dedicated, isolated sending infrastructure with their own IPs; that is Infraforge, and Mailforge's shared tier is explicitly the budget option.
- Anyone unwilling to run warm-up separately and ramp slowly; buying fifty mailboxes and sending fifty thousand emails next week will burn them regardless of how good the DNS is.

## Features

### Domain provisioning

The first half of the job, and the part people underestimate.

- **Bulk domain registration**: Register secondary sending domains in bulk at about $14 a year for a .com, so your primary company domain never appears in a cold campaign and never carries the reputation risk.
- **Bring your own domains**: Existing domains can be connected instead of purchased, with Mailforge taking over the DNS configuration on them.
- **Domain-count calculator**: Enter sequence length, mailboxes per domain, and monthly contact volume and the tool computes how many domains and slots you actually need, which prevents the classic mistake of stacking thirty mailboxes onto one domain.
- **SSL and domain masking add-on**: For $2 a month or $6 a year per domain, sending domains get SSL and can be masked to redirect to your real site, so a curious prospect who types the domain into a browser does not land on a blank page.

### Automated DNS and authentication

The reason to pay rather than do this yourself.

- **SPF configured for you**: The Sender Policy Framework record authorizing your sending servers is written automatically, correctly, and without the syntax mistakes that silently fail authentication.
- **DKIM keys generated and published**: DomainKeys Identified Mail signing keys are created and the public key is published in DNS per domain, so receiving servers can verify your mail was not tampered with.
- **DMARC policy published**: A DMARC record is set up for each domain, which since 2024 is effectively mandatory for anyone sending to Gmail and Yahoo at any meaningful volume.
- **MX and nameserver handling**: Mail exchanger records and nameservers are pointed correctly at provisioning time rather than left as a manual step you discover only when nothing arrives.
- **Automated setup at scale**: The whole authentication ritual runs identically across every domain you buy, which is the difference between ten domains being safe and ten domains having one misconfigured record you never notice.

### Mailbox management

Slot-based capacity rather than per-mailbox billing.

- **Slot-based pricing**: You buy capacity, not specific mailboxes. Deleting a mailbox frees its slot for a new one at no additional charge, which matters because burned mailboxes get retired regularly in real outbound programs.
- **Bulk mailbox creation**: Create mailboxes across many domains at once with generated naming rather than typing each address into a provisioning form.
- **Ten-slot minimum**: The smallest purchase is ten slots, roughly $30 a month annually or $50 monthly, which sets the true entry price for the product and rules out very small users.
- **Inbox hosting and maintenance included**: The subscription covers hosting and ongoing upkeep of the mailboxes, not just the initial provisioning.
- **Credential export to sequencers**: Mailbox credentials export cleanly into Instantly, Smartlead, Salesforge, and other sending platforms as standard connected accounts.

### Reputation protection across a pool

How infrastructure limits damage when something goes wrong.

- **Domain isolation**: Spreading mailboxes across many cheap secondary domains means a domain that gets blacklisted costs you $14 and a few mailboxes rather than your company's email reputation.
- **Recommended mailboxes per domain**: The calculator pushes a small number of mailboxes per domain, which is the correct pattern: concentration is what turns a single spam complaint cluster into a domain-wide problem.
- **Shared infrastructure tradeoff, stated plainly**: Mailforge is the shared tier of the Forge Stack. It is cheaper than real Workspace mailboxes and cheaper than dedicated infrastructure, and the cost of that is that you share sending infrastructure with other customers whose behavior you do not control. Primeforge and Infraforge exist because that tradeoff is not right for everyone.
- **Separation from your primary domain**: The entire architecture exists so cold outbound never touches the domain your invoices, contracts, and customer support run on, which is the single most valuable thing infrastructure buys you.
- **Warm-up handled separately**: Warm-up is not bundled; it comes from Warmforge or from whatever your sending platform includes. Provisioning is not warming, and treating a fresh mailbox as ready to send is the most common way people waste this purchase.

### Ecosystem and integration

Part of the Forge Stack, but usable on its own.

- **Works with third-party sequencers**: Instantly, Smartlead, and other platforms connect Mailforge mailboxes as ordinary accounts; you are not locked into Salesforge to use it.
- **Native fit with Salesforge and Agent Frank**: Tightest integration is with the vendor's own sending platform and AI SDR, which is the intended full-stack path.
- **Warmforge pairing**: The sibling warm-up product is designed to pick up Mailforge mailboxes directly, which removes one configuration step if you buy both.
- **No contract**: Cancel anytime on monthly billing; annual billing buys two months free but locks the term.

## Use cases

- **Founder launching outbound for the first time**: They have picked a sending platform but have no idea how many domains they need or how to write a DKIM record, and they are one bad decision away from getting their real company domain filtered. Outcome: The calculator sizes the setup, Mailforge registers three secondary domains and ten mailboxes with SPF, DKIM, and DMARC written automatically for about $44 a month, and the primary domain stays untouched.
- **Agency onboarding a new client campaign**: Each client needs its own isolated domains and mailboxes, and provisioning them by hand takes a day per client. Outcome: Slots are bought in bulk, mailboxes are created per client in minutes, and burned mailboxes are deleted and recreated inside existing capacity rather than triggering new charges.
- **Sales team scaling from one mailbox to twenty**: Volume has outgrown a single Workspace account, and continuing to push it harder is the fastest route to landing in spam. Outcome: Twenty slots across four domains spread the same volume thinly, each mailbox stays inside safe daily limits, and the sequencer rotates across them.
- **Operator rebuilding after a deliverability collapse**: The existing domains are burned, reputation is gone, and the campaigns are landing in spam regardless of copy. Outcome: Fresh domains and mailboxes are provisioned with correct authentication from day one, warmed through a separate warm-up product, and ramped slowly rather than reused.

## Pricing

Slot-based subscription for mailbox capacity, billed monthly or annually with a ten-slot minimum, plus separate per-year domain registration and an optional per-domain SSL add-on.

- **Mailbox slots, annual billing**: $3 per slot per month, billed yearly. Ten-slot minimum, roughly $30 per month equivalent; Two months free versus monthly billing; Automated DNS setup including SPF, DKIM, and DMARC; Inbox hosting and maintenance; Create and delete mailboxes freely inside purchased slots. The rate most buyers should take; outbound infrastructure is not something you spin up for four weeks.
- **Mailbox slots, monthly billing**: $5 per slot per month. Ten-slot minimum, $50 per month; No contract, cancel anytime; Same automated DNS and authentication setup; Same slot recycling behavior. Two-thirds more expensive than annual, which is a steep premium for flexibility.
- **Domain registration**: $14 per .com domain per year. Registered and DNS-configured inside Mailforge; Other TLDs priced separately; Bring-your-own-domain also supported; Calculator recommends how many you need.
- **SSL and domain masking add-on**: $2 per month, or $6 per year. SSL certificate on sending domains; Masking so the domain redirects to your real site; Prevents a prospect finding an empty page; Optional per domain.

Billing notes:

- Annual billing at $3 a slot includes two months free against the $5 monthly rate, a 40 percent difference that is unusually large even by SaaS standards.
- The ten-slot minimum sets a real floor of about $30 a month annually or $50 monthly before domains, so this is not a product for someone who wants two extra mailboxes.
- Domains are billed separately at roughly $14 a year for a .com and are not included in slot pricing, so a realistic ten-mailbox, three-domain setup is about $30 a month plus $42 a year.
- Slots are capacity rather than named mailboxes, so retiring a burned mailbox and creating a replacement costs nothing extra, which is a genuinely better model than per-mailbox billing for real outbound.
- Warm-up is not included and is sold as a separate Forge Stack product, so budget for it or for whatever your sending platform bundles.
- There is no free trial, because every slot has a real hosting cost behind it.

Value assessment: At $3 a slot annually, Mailforge is among the cheapest ways to get authenticated mailboxes at scale. Model it properly: sending 10,000 emails a month at a conservative 30 a day per mailbox needs roughly eleven to fifteen mailboxes, so about $45 a month of slots plus two or three domains, which is genuinely cheap next to the sequencer bill. At 100,000 a month you need on the order of 110 to 150 mailboxes, about $330 to $450 a month of slots plus twenty to thirty domains, and at that point the shared-infrastructure question becomes the real decision rather than the price. Compare that against Primeforge at $4.50 a slot for genuine Workspace and Microsoft 365 mailboxes and the premium for real provider mailboxes is only about 50 percent, which is a smaller gap than most buyers assume.

## Strengths

- Removes the single most tedious and error-prone part of running cold email, which is provisioning domains and writing SPF, DKIM, and DMARC records correctly at scale.
- Slot-based pricing means deleting and recreating burned mailboxes costs nothing, which matches how outbound programs actually behave.
- At about $3 a mailbox per month on annual billing, it is at the cheap end of the infrastructure market.
- The sizing calculator is genuinely useful and steers new buyers away from stacking too many mailboxes on one domain.
- Works with third-party sequencers including Instantly and Smartlead, so buying it does not commit you to the vendor's own sending platform.
- Part of a coherent product ladder, so upgrading to real Workspace mailboxes or dedicated infrastructure is a move within one vendor rather than a migration.
- Domain registration, DNS, hosting, and maintenance all arrive on one bill instead of three vendors.

## Limitations

- It is not a sending platform, so it is always a second purchase alongside a sequencer, which some buyers do not realize until after checkout.
- Shared infrastructure means you do not control the sending behavior of other customers on the same platform, which is precisely why the vendor also sells Primeforge and Infraforge.
- No warm-up included, so a fresh Mailforge setup is not ready to send at volume on day one and needs another subscription.
- Ten-slot minimum excludes small users who just want two or three extra mailboxes.
- No free trial, so evaluation means paying for at least a month of real infrastructure.
- Monthly billing at $5 a slot is a 67 percent premium over annual, which pressures buyers into a year commitment early.
- Mailboxes from a shared cold email infrastructure provider are not the same asset as a real Google Workspace account, and some receiving domains treat them accordingly.

## Comparisons

- **Mailforge vs Primeforge**: Same company, same DNS automation, different mailbox substrate. Primeforge sells genuine Google Workspace and Microsoft 365 mailboxes with US IP addresses at $4.50 a slot, while Mailforge sells cheaper shared infrastructure at $3. If inbox placement into Gmail-heavy prospect lists is the whole game, the 50 percent premium for real provider mailboxes is usually worth it; if you are running very high volume where cost per mailbox dominates, Mailforge is the budget position.
- **Mailforge vs Zapmail**: Zapmail sells pre-warmed Google and Microsoft mailboxes from $39 a month for ten, roughly $3.90 each, with pre-warming as the headline. Mailforge is cheaper per slot at $3 annually but warms nothing. If the pre-warmed claim matters to your timeline, Zapmail removes weeks; if you already run a warm-up product, Mailforge costs less for the same provisioning job.
- **Mailforge vs Maildoso**: Maildoso goes much cheaper at scale, down to $0.49 a mailbox at a thousand, using its own SMTP infrastructure with IP rotation and self-healing mailboxes, but recommends only about fifteen cold emails a day per mailbox. Mailforge is more expensive per mailbox and more conventional. High-volume operators chasing cost per mailbox take Maildoso; buyers who want fewer, better-behaved mailboxes take Mailforge or Primeforge.
- **Mailforge vs Instantly**: Not competitors: Instantly is the sending platform and Mailforge is what you plug into it. Instantly does sell its own done-for-you accounts marketplace, so there is overlap at the point of purchase, and buying both from Instantly is simpler. Buying Mailforge separately is usually cheaper per mailbox and keeps your infrastructure portable if you ever change sequencer, which is the stronger long-term argument.
- **Mailforge vs ListKit**: ListKit bundles data, infrastructure, inboxes, and sending into one $597 a month package with domains included. Mailforge unbundles the infrastructure piece for about a tenth of that but leaves you to buy leads and a sequencer separately. Teams that want one invoice and a concierge take ListKit; teams that want to control and price each layer take Mailforge plus their own sequencer.

## Implementation

- Setup time: Minutes to buy and provision, but plan for two to three weeks before meaningful volume. Domains register and DNS propagates quickly, mailbox creation is bulk and fast, and then warm-up and ramp-up set the real timeline.
- Learning curve: Low for the tool, moderate for the discipline. The interface is a calculator and a provisioning screen. What is hard is knowing how many mailboxes per domain to run, what daily caps to hold, and when to retire a mailbox, and Mailforge helps with the first of those and not the others.
- Onboarding: Fully self-serve checkout with no sales call. Customer support is included in the subscription, and the calculator does most of the advisory work a sales call would.
- Migration: Existing domains can be brought in and reconfigured, which avoids re-registering. Moving away means pointing DNS elsewhere and losing the hosted mailboxes, so treat your domains as the portable asset and the mailboxes as disposable. Because mailbox credentials connect to any sequencer, changing sending platform does not require changing infrastructure.

## Platform, API & security

- Platforms: Web app, Bulk domain and mailbox provisioning console
- API: API access is marketed on the sibling Primeforge product; Mailforge itself is primarily a provisioning console, with mailbox credentials exported for connection to sending platforms.
- Compliance: SPF, DKIM, and DMARC configured automatically on every provisioned domain, Sender obligations under CAN-SPAM and GDPR remain entirely with you as the sender, since Mailforge supplies infrastructure and never touches your campaign content
- Data residency: Not published as a selectable option; confirm with the vendor if regional hosting is a requirement.
- SSO: Not advertised.
- Security notes: Mailboxes are provisioned on shared cold email infrastructure rather than as individual Google Workspace or Microsoft 365 tenants, which is the core architectural difference from the sibling Primeforge product and the main thing to understand before buying. SSL and domain masking are available as a paid add-on per domain.

## Support

- Channels: Email support, In-app support, Support included in every subscription
- Documentation: Documentation covering domain setup, DNS automation, mailbox provisioning, and connecting mailboxes to third-party sending platforms.
- Community: Active audience around the Salesforge founder's public content on outbound and deliverability.

## Company

- Founded: 2022
- Founders: Frank Sondors
- Headquarters: Tallinn, Estonia
- Ownership: Founder-led, largely bootstrapped with a small early round
- Employees: Small team; exact headcount not disclosed
- Funding: Salesforge, the parent, reported a pre-seed round of approximately $500K in 2024 and has otherwise grown on revenue; the company reported reaching roughly $3M ARR within about a year of launching its first product.

Timeline:

- 2022: Salesforge is founded in Tallinn by Frank Sondors, with the first product going live the following year.
- 2023: The Salesforge sending platform launches, and the need for cheap, correctly configured sending infrastructure underneath it becomes obvious.
- 2024: Mailforge launches as the shared cold email infrastructure tier of the Forge Stack, automating domain registration, DNS, SPF, DKIM, and DMARC at bulk scale.
- 2024: Salesforge raises a pre-seed round of approximately $500K and expands the Forge Stack with Primeforge for real Workspace and Microsoft 365 mailboxes.
- 2025: The stack settles into six products covering sending, AI SDR, lead search, shared infrastructure, private infrastructure, and warm-up, with Mailforge positioned as the budget infrastructure option.

## Integrations

Instantly, Smartlead, Salesforge, Warmforge, Other IMAP and SMTP compatible sending platforms, Your existing domain registrar via nameserver transfer

## FAQ

### What is Mailforge and is it a sending platform?

Mailforge is mailbox infrastructure, not a sending platform. It registers domains, provisions mailboxes in bulk, and configures SPF, DKIM, and DMARC automatically, then hands you credentials to connect into a sequencer like Instantly, Smartlead, or Salesforge. It has no sequences, no unified inbox, and no campaign reporting, so it is always bought alongside a sending tool rather than instead of one.

### How much does Mailforge cost per mailbox?

About $3 per mailbox slot per month on annual billing, or $5 per slot on monthly billing, with a ten-slot minimum. That makes the realistic entry point roughly $30 a month annually or $50 monthly. Domains are separate at about $14 a year for a .com, and SSL with domain masking is an optional $2 a month or $6 a year per domain.

### Does Mailforge set up SPF, DKIM, and DMARC for me?

Yes, and this is the main reason to buy it. DNS configuration is automated across every domain you register or connect: nameservers, MX, SPF, DKIM key generation and publication, and a DMARC policy. Doing that by hand across twenty domains is where most people introduce the silent misconfiguration that ruins deliverability without any visible error.

### What is a mailbox slot and why does it matter?

A slot is capacity rather than a specific address. You are billed for slots purchased, not mailboxes currently active, so you can delete a burned mailbox and create a replacement inside the same slot at no extra cost. That matters because retiring damaged mailboxes is a routine part of running outbound, and per-mailbox billing would penalize you for good hygiene.

### Does Mailforge include email warm-up?

No. Warm-up is a separate product in the Forge Stack called Warmforge, or you can use whatever warm-up your sending platform bundles. A freshly provisioned mailbox with perfect DNS is still a brand-new sender with no reputation, and sending real volume from it immediately is the fastest way to waste the purchase. Budget two to three weeks of warm-up and gradual ramp before meaningful sending.

### How does Mailforge protect domain reputation across a pool of mailboxes?

Structurally rather than magically. It pushes you to spread a small number of mailboxes across many cheap secondary domains, so a domain that gets blacklisted costs $14 and a few mailboxes instead of your company's real email reputation. Your primary domain never appears in a cold campaign. The calculator enforces the mailboxes-per-domain discipline that most people get wrong on their own.

### How is Mailforge different from Primeforge?

Same company and same DNS automation, different mailbox substrate. Primeforge provisions genuine Google Workspace and Microsoft 365 mailboxes with US IP addresses at $4.50 a slot. Mailforge provisions cheaper shared cold email infrastructure at $3 a slot. Real provider mailboxes generally place better into Gmail and Outlook inboxes, so the 50 percent premium is often worth paying; Mailforge is the option when cost per mailbox dominates.

### Can I use Mailforge mailboxes with Instantly or Smartlead?

Yes. Mailbox credentials connect to Instantly, Smartlead, Salesforge, and other IMAP and SMTP compatible sequencers as ordinary sending accounts. You are not locked into the vendor's own sending platform, which also means your infrastructure stays portable if you change sequencer later.

### How many mailboxes do I need for my volume?

Work backwards from a conservative daily cap. At around 30 cold emails a day per mailbox, 10,000 emails a month needs roughly eleven to fifteen mailboxes, about $45 a month of slots plus two or three domains. 100,000 a month needs on the order of 110 to 150 mailboxes, roughly $330 to $450 a month of slots plus twenty to thirty domains. Mailforge's calculator does this arithmetic for you at checkout.

### Is there a free trial?

No. Every slot carries real domain registration and hosting costs, so the vendor sells no trial. The smallest genuine evaluation is one month of ten slots, about $50 on monthly billing plus a domain, which is a reasonable amount to risk on finding out whether the provisioning workflow suits you.

## Editorial verdict

Mailforge does one unglamorous job well: it turns the multi-hour ritual of registering domains and hand-writing SPF, DKIM, and DMARC records into a calculator and a checkout, at about $3 a mailbox per month. If you have already picked a sending platform and need ten to a few hundred secondary mailboxes without touching your company domain, it is among the cheapest and least annoying ways to get them, and slot-based billing correctly rewards retiring burned mailboxes. Two things should govern the decision. First, this is infrastructure, not a sequencer, and it is always a second bill. Second, it is the shared tier of a ladder whose upper rungs exist for a reason: if inbox placement is your binding constraint rather than cost per mailbox, the extra $1.50 a slot for real Workspace mailboxes from Primeforge is usually the better buy.

## SaaSTracker awards

- Innovation (Cold Email Outreach, Summer 2026): "Bulk domain and mailbox provisioning with the DNS done automatically collapsed a week of deliverability setup into a checkout flow."

---

Source: SaaSTracker (https://saastracker.org), an independent editorial project. This profile is compiled from public information, carries no peer reviews or paid placement, and was last reviewed 2026-08-22. Awards are judged on published criteria: https://saastracker.org/methodology