Mailforge Alternatives: 4 Cold Email Infrastructure Tools for 2026

Mailforge is a cold email infrastructure platform from Salesforge. It automates domain purchasing, mailbox creation, and SPF, DKIM, and DMARC setup: shared-IP infrastructure is ready in about five minutes and connects to any sequencer.

The product works, and users rarely complain about the mechanics. The problem is the price. Mailforge charges $3 per mailbox per month, while SMTP mailboxes on the market start at around $1 in 2026, and Maildoso offers them at $0.49 at volume. For a team with 300 mailboxes, the difference adds up to hundreds of dollars every month, and that is usually what starts the search for alternatives.

In this article, we review four Mailforge alternatives for different needs: cheap SMTP at scale with full API and MCP access, unlimited mailboxes for a flat fee, bundled plans with built-in warmup, and real Google Workspace accounts. We deliberately left out Infraforge and Primeforge: they belong to the same Forge ecosystem as Mailforge, so switching to them does not mean changing vendors.

Price: reason number one. According to our data, cost comes up in most migration requests. Mailforge charges $3 per mailbox per month with a 10-slot minimum. Competitors sell SMTP mailboxes at roughly $0.75 to $1 at volume (Maildoso goes as low as $0.49 on large packages). For example, 300 mailboxes cost $900 per month at Mailforge, while a comparable package at Maildoso costs $225. Over a year, the difference pays for a solid sequencer plus a lead database.

No built-in warmup. Mailforge sells infrastructure only. Warmup lives in a separate product, Warmforge, with its own subscription. There is a free tier, but it still means another account, another integration, and another point of failure in your stack.

A shared IP pool without active rotation. Your sender reputation is shared with other people's campaigns: one "neighbor" sending spam from the same IP drags down placement for everyone. Mailforge has no mechanism that automatically replaces burned IPs. If an address lands on a blacklist, you have to work it out with support.

No real Google Workspace or Microsoft 365 mailboxes. Mailforge sells its own SMTP only. For B2B campaigns that is usually enough: according to our data, well-configured SMTP mailboxes generally deliver well, including to Google inboxes. That said, it is widely believed that when you target @gmail.com and other consumer providers, emails from "real" Google accounts sometimes pass filters more easily (the ESP matching effect), and having such mailboxes in your stack is useful at least for diversification. To be fair, real Google and Microsoft accounts are sold by Primeforge, another Forge ecosystem product, so the same company does cover this scenario. But it is a separate product with a separate subscription, not a Mailforge feature.

No free trial. You cannot test deliverability before paying: you can create an account, but it is useless until you buy domains and mailboxes.

One thing that is not a reason to switch: paying for domains. Domains are an external cost with every provider. Some include them in packages, some sell them separately, but you pay for them everywhere. Compare providers on per-mailbox price and total cost of ownership, not on whether "domains" appears as a line item.

We scored each alternative on six parameters.

Infrastructure type. Shared IPs (cheap, but your reputation depends on your neighbors), dedicated IPs (more control, but pricier and more fragile: one blacklist takes the IP down), or real Google/Microsoft accounts (the best placement on consumer addresses, but more expensive and with strict limits).

Real price per mailbox. Not the landing page headline, but the cost at your volume, including required domains and paid add-ons.

API and MCP. In our experience, this is the criterion that separates "manage by hand" infrastructure from "built to scale" infrastructure in 2026. An API lets you register domains, create mailboxes, and configure DNS records programmatically, then export mailboxes to your sequencer automatically, with no clicking through an interface. An MCP server (Model Context Protocol) goes further: it connects the infrastructure to AI assistants like Claude, so routine work ("register 20 domains, create 60 mailboxes, export to Instantly") runs from a single natural-language command. For agencies that set up infrastructure for every client, and for teams whose outbound operations run on scripts, no API means hours of manual work every week.

Reputation protection. IP rotation, automatic mailbox recovery, placement tests, blacklist monitoring. Since 2024, Google requires bulk senders to authenticate with SPF/DKIM/DMARC and to keep spam complaint rates below 0.3% (see Google's official sender guidelines and the complaint threshold in the Postmaster Tools help center); in 2025, Microsoft introduced similar requirements for high-volume senders to Outlook. Infrastructure that does not monitor reputation automatically shifts that work onto you.

Warmup. Built in, sold as an add-on, or absent.

Entry terms. Trial, refund guarantee, minimum purchase.

Prices are valid as of July 2026, per the providers' official pages. Monthly subscriptions only.

A reminder about the conflict of interest: Maildoso is our product. Below we describe what it does, what it costs, and where its limits are.

Maildoso is an infrastructure platform in the same class as Mailforge: domain registration, mailbox creation, automatic SPF, DKIM, and DMARC setup, export to any sequencer. There are three differences: price, the way reputation protection works, and the depth of automation.

Price. Monthly SMTP plans (as of July 2026): 30 mailboxes for $75 ($2.50 per mailbox), 300 for $225 ($0.75), and 1,000 for $499 ($0.49 per mailbox). Custom packages start at $0.49 per mailbox. Domains are purchased separately at $12 per year. For comparison: the same 300 mailboxes cost $900 per month at Mailforge versus $225 at Maildoso. There are no discounts or promos on principle: everyone pays the same price. The current price list is published on the pricing page.

Besides SMTP, Maildoso sells real Google Workspace accounts with an official business license, on their own or in combo plans together with SMTP. This covers a scenario Mailforge does not address at all: campaigns to @gmail.com and other consumer providers, where real Google accounts are traditionally considered the more reliable option.

API and MCP on all plans. This is what we see as the main functional difference. The Maildoso API covers the full cycle: domain registration (or connecting your own domains), mailbox creation, DNS record setup, and pushing credentials straight into your sequencer. Instantly, Smartlead, and EmailBizon connect in one click; everything else connects through the API. The MCP server adds control from an AI assistant: connect Maildoso to Claude and you can deploy infrastructure with a chat command, for example "create 10 domains, 8 mailboxes each, export to Smartlead." For an agency that builds infrastructure for every new client, this is the difference between hours of manual setup and a single prompt. Important: API and MCP access is included in every plan, with no extra fees and no enterprise gating.

Reputation protection. Campaigns are sent from different IP addresses in a pool spread across 35 data centers, and if an IP gets flagged or blacklisted, the system automatically swaps it for a clean one. You will not even notice. Mailboxes run in self-healing mode: a "burned" mailbox is automatically pulled from campaigns for 14 days to recover its reputation. Placement tests run every 3 days, and every mailbox shows a current health score. CAPTCHA protection hides the domain from automated scanning.
Entry terms. There is a 300-mailbox trial package so you can test deliverability on your own campaigns before a full contract, plus a 30-day money-back guarantee on SMTP plans.

Downsides. The recommended limit is 15 cold emails per day per mailbox: Maildoso's strategy is built on "many mailboxes, low volume each," so you will need more mailboxes for a given daily volume than with providers that allow 30–50 emails. There is no built-in warmup; if your scenario needs it, you will have to plug in an external tool. The dashboard focuses on infrastructure metrics, so users go to their sequencer for deep campaign analytics. Finally, Maildoso's SMTP mailboxes are optimized for B2B: for targeting personal addresses, we ourselves recommend the Google Workspace mailboxes or a combo plan.

Who it fits. Teams and agencies whose main criteria are per-mailbox price at volume and automation through API/MCP, and anyone who wants to test the infrastructure before paying for a contract.

Inframail builds its infrastructure entirely on the Microsoft cloud with dedicated US IPs and sells it under a model that is rare in this market: not per mailbox, but as a flat subscription with unlimited mailboxes.

Price. The Unlimited plan costs $129 per month: one dedicated US IP and a cap of 80,000 emails per month. The Agency plan costs $327 per month: three dedicated IPs and a 300,000-email cap. In both cases you can create as many mailboxes as you want; you pay for IPs and sending volume.

Strengths. A predictable budget: an agency that constantly adds and replaces mailboxes pays the same amount no matter how many it runs. Dedicated IPs mean your sender reputation belongs to you alone, with no "neighbors." Notable features include Phantom Redirect, which hides domain redirects from mailbox providers, and automatic blacklist removal with a claimed 68.3% success rate.

Downsides. Microsoft only: there is no Google infrastructure at all, which rules out provider diversification and lowers placement for campaigns targeting Gmail addresses. A dedicated IP cuts both ways: if it does land on a blacklist, all of your sending suffers, and there is no automatic rotation like on shared pools. No built-in warmup. No trial. And at low mailbox counts, the flat price works against you: 20 mailboxes at Inframail cost the same $129 as 500.

Who it fits. Agencies and teams with a large, constantly changing fleet of mailboxes who value budget predictability and dedicated IPs over Google/Microsoft diversification.

Mailscale is SMTP infrastructure focused on launch speed: the service promises 50+ mailboxes created in under a minute, with automatic DNS setup and a CSV file of credentials you can import into any sequencer.

Price. Plans are fixed (as of July 2026): Solopreneur at $79 per month for 15 mailboxes ($5.27 per mailbox), Business at $119 for 50 ($2.38), Enterprise at $249 for 200 ($1.25, extra mailboxes at $1.50). The Unlimited plan with dedicated IPs and a personal deliverability consultant starts at $1,000 per month. Domains are purchased inside the platform from $9 per year (realistically closer to $13 for a .com), with up to 5 mailboxes per domain. Mailscale has no public pricing page on its website; you have to look up current numbers in their knowledge base. Every plan comes with a 7-day free trial.

Strengths. Warmup is built into the plan, so you do not need a separate tool, which noticeably simplifies the stack for a beginner. The entry barrier is low: a trial with no credit card, launch within minutes. Higher plans include access to a deliverability consultant and a guarantee: 95–100% placement during the first two weeks of warmup, or your money back.

Downsides. The biggest one for automation: there is no public API. The only way to get mailboxes out of Mailscale is a manual CSV export. For an agency that deploys infrastructure with scripts, that is a dealbreaker. Plan boundaries are rigid: if you need 60 mailboxes, you either pay for 200 or buy extras at $1.50 each. There are no refunds after mailboxes are activated, so the trial is your only testing window. You cannot bring your own domains; purchases happen inside the platform only. And placement reviews are mixed: alongside a high G2 score (4.8), Trustpilot sits lower (4.1), and the cluster of negative reviews is specifically about deliverability on shared IPs after warmup ends.

Who it fits. Solo founders and small teams who want the fastest all-in-one start with warmup included, and who manage infrastructure by hand rather than with code.

Zapmail is a reseller of Google Workspace and Microsoft 365 mailboxes for cold email. The service takes over the slow part (buying domains, setting up SPF, DKIM, DMARC, and MX records, creating accounts) and deploys a fleet of mailboxes in about five minutes.

Price. From $39 per month, which works out to roughly $3–3.5 per mailbox. That is more expensive than SMTP providers, but you are paying to send from the same provider's infrastructure your recipient uses.

Strengths. It is widely believed that thanks to ESP matching, an email from a real Google account to a Gmail address sometimes passes filters more easily than an email from an unfamiliar SMTP server, though in practice a lot depends on the setup and reputation of the specific infrastructure. Each domain gets an isolated workspace, so a problem on one domain does not spread to the others. For teams whose audience lives on Gmail and Outlook, this is the most direct path to the inbox.

Downsides. The API is available only on the Pro plan at $299 per month. On lower plans, automation is simply not available, which looks dated given our focus on programmatic infrastructure management. There are no refunds at all, and no trial either: the starter plan is effectively your test drive. Some users report accounts with Indian IPs instead of US ones, which is a risk factor for campaigns targeting the US market. There is no built-in warmup. And sending limits on real Google accounts are more conservative than on SMTP: you need a comparable number of mailboxes for the same daily volume, and they cost more.

Who it fits. Teams targeting a Gmail/Outlook audience who are ready to pay a premium for ESP matching and accept the limits on API access and refunds.

Per-mailbox prices are misleading because providers recommend different daily limits. We ran a common scenario (a steady 10,000 cold emails per day) through each provider's monthly plans. One important note: cold emails are usually sent on business days only, which means 20–22 sending days per month, or roughly 200,000–220,000 emails of monthly volume. The numbers are rounded and domains are counted separately; treat this as a reference point, not a quote.

• Mailforge. At a conservative 15 emails per mailbox, you need ~667 slots: about $2,000/mo (at $3 per slot), plus domains. The most expensive option in this scenario.
• Maildoso. The same ~666 mailboxes at the current $0.75 rate cost about $500/mo; domains are paid separately ($12 per year each). For almost the same amount ($499), you can take the next plan in the lineup, 1,000 mailboxes, and raise your sending ceiling to 15,000 emails per day.
• Inframail. 10,000 emails per day on business days comes to about 210,000 emails per month. That fits within the Agency plan cap (300,000 emails) at $327/mo with three dedicated IPs, leaving about 40% headroom. But it is Microsoft infrastructure only.
• Mailscale. At the recommended 30–50 emails per mailbox, you need 200–334 mailboxes: the Enterprise plan at $249/mo covers 200, extras cost $1.50 each, so roughly $250–450/mo plus 40–67 domains inside the platform. Warmup included.
• Zapmail. Real Google accounts at a conservative ~15–25 emails per day require 400–667 mailboxes: roughly $1,200–2,300/mo plus domains. Comparable to Mailforge and more expensive than any SMTP option.

The takeaway: at 10,000 emails per day, the cheapest options are Inframail ($327, if Microsoft-only works for you) and Maildoso (~$500, with the option to move up to 1,000 mailboxes for $499 and raise the sending ceiling to 15,000 emails per day); Mailscale sits in the middle with warmup included; Mailforge and Zapmail cost several times more in this scenario.

Lowest price at volume plus automation. If you manage infrastructure through an API, scripts, or an AI assistant, and you count per-mailbox cost across hundreds of units, go with Maildoso. Full API and MCP on all plans, IP rotation, and prices down to $0.49 per mailbox.

Fixed budget and dedicated IPs. If your mailbox fleet is large and changes constantly, and your budget has to be predictable, Inframail fits. Keep in mind: Microsoft only, and static IPs.

Fast all-in-one start. If you are launching your first outbound campaign and do not want to assemble infrastructure and warmup piece by piece, start with Mailscale and its 7-day trial. There will be no API automation.

Targeting a Gmail audience. If your recipients use personal Gmail addresses, you need real Google accounts: Zapmail, or Maildoso's Google Workspace mailboxes / combo plan.

And a universal recommendation from our own practice: at 100+ mailboxes, do not depend on a single provider. Keep a primary and a backup, so that one price change, one blacklist incident, or one slow support reply does not stop your entire outbound.