Mailforge Alternatives in 2026: Why StackMail Is the Cheaper Drop-In
Last updated: 2026-05-04 - written and reviewed by the StackMail team. We are a competing provider; this comparison is honest about both products. Verify pricing on Mailforge before purchase as plans change.
The short answer
Mailforge is the cold email infrastructure arm of the Salesforge family - a polished, well-marketed product priced at $3/mailbox monthly or roughly $2.50 annual that wins on ecosystem reach (Salesforge sequencer + Primeforge MS365 + Infraforge private infra + Warmforge warmup) and a thick cross-linking moat across 5-7 Forge domains. StackMail is the independent alternative at $2.50/mailbox annual: same Google Workspace and Microsoft 365 mailboxes, same automated SPF/DKIM/DMARC, same sequencer compatibility, but no Forge-account upsell pressure in your dashboard and no implicit pull toward a single sequencer brand. If you are already deep in Forge Stack, Mailforge is the natural pick. If you sequencer-shop or want clean separation between mailbox infra and sending tool, StackMail is the cleaner buy.
Our verdict
Pick Mailforge if you have already standardized on Salesforge as your sequencer (or plan to), if you value the convenience of a single billing relationship across mailboxes, warmup, sequencer, and AI SDR, and if you actively benefit from the cross-product features that the Forge ecosystem ships. The product is good, the pricing is genuinely competitive, and the cross-domain content moat means Mailforge content is easy to find when you need answers. Pick StackMail if you want the same $2.50/mailbox economics without the ecosystem gravity, if you sequencer-shop (some campaigns on Instantly, some on Smartlead, some on Apollo) and need a mailbox layer that does not subtly tilt you toward one sender, or if you simply prefer transparent per-mailbox pricing without the calculator-style pricing-by-usage model. The mailboxes themselves are the same product on both sides - Google issues them and Microsoft issues them; we are both resellers. What changes is whether the dashboard you log into every day is part of a five-product family or a single-purpose mailbox tool.
Why people search for Mailforge alternatives
Mailforge is the cold email infrastructure product in the Salesforge group - a constellation of cold outreach tools that includes Salesforge (the sequencer and AI SDR), Primeforge (Microsoft 365 mailboxes), Infraforge (private/dedicated infrastructure), Warmforge (warmup as a service), Leadsforge (prospecting), and Agent Frank (the AI SDR layer). The Forge family is one of the better-executed ecosystem plays in cold email - each product has its own brand, its own landing page, and its own pricing surface, but they cross-link aggressively and they bundle smoothly when you adopt more than one. Mailforge specifically targets the bottom of the funnel with the line "Cold Email Infrastructure Sorted In Minutes" and a calculator-driven pricing model that lands at $3/mailbox monthly or roughly $2 effective annual when you commit for a year on volume.
We wrote this page because the dominant searches for "mailforge alternative" come from two profiles. The first is the agency owner or growth marketer who tried Mailforge, liked the provisioning UX, but bumped into the ecosystem gravity - every product surface gently nudges you toward the rest of Forge Stack, and if you are running Smartlead or Apollo or Instantly as your sequencer, that pull is friction rather than feature. The second is the price-shopper at 100-300 mailbox scale who is comparing Mailforge against the rest of the category (Zapmail, InboxKit, Inframail, Maildoso, StackMail) and wants an honest read on where each one actually wins. This page is for both profiles. We will not pretend StackMail beats Mailforge on every dimension - their content moat across the Forge family is real, their warmup integration with Warmforge is genuinely smooth, and Salesforge is a credible sequencer in its own right. We will be honest about both sides.
Before going further, the structural fact about this category: the underlying mailbox is a Google Workspace seat or a Microsoft 365 seat that costs Google or Microsoft about $6/seat/month wholesale to a reseller. Every cold email infrastructure provider - Mailforge, StackMail, InboxKit, Zapmail, Primeforge, Inframail, Maildoso, Hypertide - is a Google Workspace authorized reseller (or Microsoft Cloud Solutions Provider) that buys those seats wholesale and resells them with automation on top. The automation layer is what you are actually paying for: bulk domain registration, automated SPF/DKIM/DMARC configuration, mailbox creation in batches, warmup orchestration, sequencer connection helpers, and a dashboard. The pricing differences across the category exist because each provider stacks a different margin on top of the same underlying $6 seat, and bundles a different set of auxiliary features into the headline. Mailforge bundles in Forge Stack ecosystem reach. StackMail bundles in independence and a fully free standalone tool suite. The mailbox is the same.
Mailforge vs StackMail: Feature comparison
Side-by-side on the features that matter for cold email infrastructure: mailbox provider, DNS automation, warmup, sequencer integrations, monitoring, support, and pricing.
| Feature | Mailforge | StackMail |
|---|---|---|
| Google Workspace mailboxes | Yes | Yes |
| Microsoft 365 mailboxes | Via Primeforge | Yes |
| Custom domain provisioning | Yes | Yes |
| Automated SPF / DKIM / DMARC | Yes | Yes |
| Bulk DNS updates across domains | Yes | Yes |
| Domain transferring between workspaces | Yes | Yes |
| Multiple workspaces per account | Yes | Yes |
| Pre-warmed mailboxes on delivery | Via Warmforge | Yes |
| Built-in mailbox warmup (no add-on) | No | Yes |
| Sequencer-agnostic (any sender) | Yes | Yes |
| Sister sequencer product (Salesforge) | Yes | No |
| Sister AI SDR product (Agent Frank) | Yes | No |
| Dedicated IP / private infra option | Via Infraforge | Coming soon |
| SSL / Domain Masking add-on | $2-6/mo | Included |
| Flat per-tier pricing on homepage | No | Yes |
| Per-mailbox cost at 100+ (annual) | $2.50 | $2.50 |
| Per-mailbox cost at 300+ (annual) | $2.50 | $2.50 |
| Minimum mailbox purchase | 10 slots | 10 (Starter) |
| Free public SPF / DKIM / DMARC tools | No | Yes |
| Free public inbox placement test | No | Yes |
| Free public blacklist checker | No | Yes |
| Independent (no ecosystem upsell) | No | Yes |
| Mailboxes you own in your own admin console | Yes | Yes |
Pricing breakdown at scale
Per-mailbox cost matters most when you scale past 30 mailboxes. Here is what a 10, 30, 100, and 300 mailbox setup costs on Mailforge versus StackMail (annual billing where available).
| Tier | Mailboxes | Mailforge / month | Per mailbox | StackMail / mailbox |
|---|---|---|---|---|
| Starter (10 mailboxes) | 10 | $30 | $3.00 | $2.50 (annual) |
| Growth (30 mailboxes) | 30 | $90 | $3.00 | $2.50 (annual) |
| Scale (100 mailboxes) | 100 | $250 | $2.50 | $2.50 (annual) |
| Custom (300+ mailboxes) | 300 | $750 | $2.50 | $2.50 (annual) |
Mailforge minimum purchase is 10 mailbox slots; $3/mailbox monthly headline. StackMail Starter is $39/mo (annual: $31).
Where Mailforge genuinely wins
We will not pretend StackMail wins on every dimension. Mailforge has real advantages worth naming.
- The Forge Stack ecosystem. This is Mailforge's single biggest moat. If you are running Salesforge as your sequencer, Warmforge for warmup, Primeforge for additional MS365 capacity, and considering Agent Frank or Leadsforge for prospecting, the unified billing and unified onboarding are genuinely valuable. We will not pretend StackMail offers an equivalent ecosystem - we are deliberately a single-purpose mailbox infrastructure product, and that is a different positioning. If you want one vendor across the entire cold email stack, Mailforge inside the Forge family is a defensible answer.
- Pricing transparency at the headline. Mailforge's "$2-3/mailbox" framing is honest, the calculator on /pricing reflects real costs, and there are no hidden onboarding fees or per-domain surcharges that surprise you at checkout. The $14/year .com domain pass-through is at-cost rather than marked up. We respect the pricing hygiene.
- Bulk DNS automation. Mailforge's bulk DNS update flow across multiple domains is one of the smoother experiences in the category. If you provision 50 domains at once, the SPF/DKIM/DMARC propagation runs cleanly without the manual fix-ups that show up on some smaller providers.
- Domain transferring between workspaces. Mailforge lets you move domains across workspaces inside the dashboard without re-provisioning. This matters for agencies that segment work by client and occasionally need to shift accounts around. It is a small feature that signals product maturity.
- SSL and domain masking. The optional SSL/Domain Masking add-on at $2-6/month is cheap insurance for branded tracking and click-protection. The fact that it is offered at the mailbox infrastructure layer (rather than as a separate vendor) is convenient.
- Cross-domain content moat. Salesforge, Mailforge, Primeforge, Infraforge, Warmforge, Leadsforge - that is six domains cross-linking with consistent design, consistent author voice, and aggressive internal SEO across the family. When you Google a niche cold email term, a Forge property is often on page 1 because of this internal-link power. From a buyer-research perspective this is genuinely useful even if you ultimately pick a different provider.
- 10k+ user claim and Salesforge customer base. The Forge family has been at this for a while and has real volume on the platform. Brand maturity matters when you are betting cold email infrastructure on a vendor for two years.
Where Mailforge falls short
The reasons people search for "Mailforge alternatives." If any of these matter to you, StackMail is the cheaper drop-in.
- Forge Stack gravity. The Mailforge dashboard, marketing site, onboarding flow, and email sequences all reference and cross-promote the rest of the Forge family. If you adopted Mailforge specifically to keep your sequencer separate (using Smartlead or Instantly or Apollo for sending), the constant nudges toward Salesforge become friction rather than feature. StackMail is deliberately ecosystem-free - we make money on mailboxes, we do not have a sequencer to upsell, so our dashboard never asks you to try a sister product.
- Calculator-style pricing without flat tiers. Mailforge's pricing-by-calculator approach (mailboxes per domain, sequences per mailbox, contacts per month) is technically more honest than flat tiers but practically harder to budget. Buyers comparing four providers want a clean "100 mailboxes = $X/month" line. StackMail, InboxKit, and Zapmail all publish flat tier prices on the homepage; Mailforge does not.
- Minimum 10-mailbox purchase. The "slots" model means you commit to capacity (10 minimum) rather than provisioning what you actually need. For a founder testing cold email at 5-mailbox scale, this is a structural barrier. StackMail's Starter at 10 mailboxes is the same minimum on paper, but our pay-as-you-grow Pro plan lets you add mailboxes one at a time after the base.
- Shared IP pool model. Mailforge's distributed infrastructure spreads mailboxes across a shared IP pool. This is fine for most senders, but if your sending strategy genuinely benefits from dedicated IPs or stricter tenant isolation, you will need to graduate to Infraforge (their dedicated infrastructure product) for an additional bill. StackMail's standard provisioning gives you isolated tenants per workspace by default.
- No fully-free public tool suite. Mailforge does not publish a fully-free SPF checker, DKIM checker, DMARC checker, blacklist checker, or inbox placement test the way StackMail does at stackmail.io/tools. The Forge family does have some free utilities scattered across the marketing properties, but they are not consolidated into a single linkable tool hub. This matters for agencies that audit deliverability mid-campaign and want quick free diagnostics.
- Warmup is a separate Forge product. Mailforge's warmup story routes through Warmforge - which is fine if you are bundling, but the unbundled experience is a second product to configure and a second pricing surface to track. StackMail includes warmup in the base mailbox price; you do not see a Warmforge-equivalent line item.
Stay with Mailforge if
- Teams already running Salesforge as their sequencer. The integration between Salesforge and Mailforge is the smoothest path in the Forge family, and the unified billing is a real convenience.
- Agencies that benefit from the Forge ecosystem (Warmforge for warmup, Primeforge for MS365 expansion, Leadsforge for prospecting) and want one vendor relationship across the stack.
- Founders who explicitly value Salesforge content, the Forge masterclass library, or community resources as part of their cold email education.
- Users who plan to grow into Infraforge for dedicated IP infrastructure - the upgrade path within the Forge family is cleaner than cross-vendor migration.
- Anyone for whom the calculator-style pricing genuinely matches their usage shape better than flat tiers do.
Switch to StackMail if
- Agencies running 50-300 mailboxes for clients on a sequencer mix (Smartlead for some, Instantly for others, Apollo for the LinkedIn-heavy ones). Mailforge's gravity toward Salesforge is friction in this workflow; StackMail's neutrality is the better fit.
- Founders who want a single, predictable per-mailbox flat rate ($2.50/mailbox annual on StackMail) rather than calculating across mailboxes-per-domain and sequences-per-mailbox dimensions.
- Teams that rely heavily on free standalone tools mid-campaign - SPF checks, DKIM verification, inbox placement tests, blacklist lookups. StackMail's free tool suite at stackmail.io/tools is fully open without signup; Mailforge does not publish equivalent consolidated free tools.
- Buyers who explicitly want clean separation between their mailbox provider and their sequencer brand. If you ever consider switching sequencers, having Mailforge inside the Forge family creates a subtle pull back toward Salesforge that you do not get with a pure-play infrastructure vendor.
- EU-based teams who want a closer-to-EU billing entity and faster response on EU-hours support without inheriting a US-marketed ecosystem layer.
- Agencies whose clients run audits and want every line item documented separately - mailbox provider, warmup, sequencer, prospecting - rather than rolled into one Forge family bill that complicates client invoicing.
How to migrate from Mailforge to StackMail (5 steps)
Practical migration playbook. Plan a 14-21 day overlap so new mailboxes warm up before you cut over - this is true regardless of which provider you switch to.
1. Export your domain and mailbox list from Mailforge
Mailforge's dashboard exposes a CSV export under each workspace. Pull the full list including domain owner, mailbox addresses, current sequencer connections, and warmup status. If you are using Warmforge alongside Mailforge, also export the warmup state and any per-mailbox notes - we cannot import the warmup history (no provider in this category can, the data lives inside each provider's warmup engine), but the snapshot is useful for client reporting continuity if you run an agency.
2. Plan a 14-21 day overlap window
Cold email mailboxes carry sender reputation that lives on the Google Workspace tenant and the IP. You do not want to swap providers mid-campaign or mid-warmup. The clean migration path is: provision new StackMail mailboxes in parallel with Mailforge, warm them for 14-21 days, then rotate them in as Mailforge mailboxes finish their current campaigns. We strongly recommend this overlap approach for any team running more than 30 mailboxes - the alternative is a hard cutover that costs you 14-21 days of sending capacity while new mailboxes warm.
3. Provision matching capacity in StackMail
Sign up at stackmail.io, pick the plan that matches your Mailforge tier (our Starter matches their 10-mailbox base, our Pro matches their 100-mailbox volume tier), and start the domain provisioning flow. We buy the .com domains at cost ($14/year pass-through, same as Mailforge), create the Google Workspace or Microsoft 365 tenant, configure DNS via automation, create the mailboxes, and start warmup - typically 10-20 minutes of wall clock time per cohort. If you are bringing your own domains rather than buying new ones, the DNS-only flow runs in under 5 minutes per domain.
4. Reconnect sequencers and disconnect Forge
Open whichever sequencer you use - Salesforge, Smartlead, Instantly, Apollo, Lemlist, Saleshandy, Reply, Outreach, Mailshake, Quickmail, Woodpecker - and disconnect the Mailforge mailboxes. Add the StackMail mailboxes via OAuth (most sequencers handle this in one click per mailbox; we have a one-click bulk-connect helper for Instantly and Smartlead specifically). If you are leaving Salesforge as well, mirror your sequence templates to the new sender first; if you are keeping Salesforge with StackMail mailboxes underneath, the OAuth flow is straightforward and we have helped customers do this exact transition.
5. Cancel Mailforge (and decide on the rest of Forge Stack)
Once your StackMail mailboxes are warmed and connected, cancel Mailforge from their billing dashboard. Important: you own the underlying Google Workspace and Microsoft 365 mailboxes - Mailforge cannot delete them when you cancel because the tenants are issued in your name, not theirs. The mailboxes stay live in your admin console; you only lose the Mailforge dashboard, the bundled Warmforge warmup automation on those specific accounts, and the cross-product Forge Stack benefits. New StackMail accounts get StackMail's warmup and dashboard. If you are also leaving Salesforge, Warmforge, or Infraforge, that is a separate decision - StackMail is mailbox infrastructure only and we do not replace those products. Plenty of customers run StackMail mailboxes underneath Salesforge as the sequencer; the two are technically compatible.
Frequently asked questions
Is StackMail actually cheaper than Mailforge, or are the headline prices the same?
At equivalent annual-billing volume tier, the per-mailbox cost is genuinely close: Mailforge lands at $2-2.50/mailbox at 100+ mailbox annual commitments, and StackMail's Pro tier is $2.50/mailbox annual. The cleaner difference is in pricing predictability - StackMail publishes flat tier prices ($31, $81, $250 per month for 10/30/100 mailboxes annual) while Mailforge runs a calculator-style model that varies by mailboxes-per-domain and sequences-per-mailbox. For agencies budgeting client retainers, the flat model is easier to quote. For the savings hunter, Mailforge's annual commitment can land slightly cheaper at very specific usage shapes; for most teams the two are within $0.50/mailbox of each other and the choice comes down to ecosystem fit rather than raw price.
Can I keep using Salesforge as my sequencer if I switch to StackMail?
Yes. Salesforge accepts external mailboxes via standard OAuth and SMTP just like every other sequencer in the category. You can keep Salesforge as your sender, drop Mailforge as your mailbox provider, and connect StackMail mailboxes underneath. The Salesforge UI does not change; the bills change. This is the lowest-disruption migration path if you specifically value the Salesforge sequencer features (the sequence builder, AI personalization, the Forge masterclass content) but want to optimize the mailbox-layer cost or stop the Forge Stack ecosystem upsell pressure on the infra side.
Will my deliverability change if I migrate from Mailforge to StackMail?
Deliverability is determined by the underlying Google Workspace or Microsoft 365 tenant, the IP range that mailbox sends from, the SPF/DKIM/DMARC configuration, and your sending behavior. All four of those are equivalent across Mailforge and StackMail because we both source mailboxes from the same upstream providers and we both configure DNS to the same authentication standards. The one structural difference is that Mailforge runs a shared IP pool by default (with Infraforge for dedicated IPs as an upgrade) while StackMail provisions isolated tenants per workspace. Real-world A/B testing across major infrastructure providers on the same domain typically shows inbox placement within 1-2 percentage points - the variation is dominated by sending behavior, not by the provider.
Does StackMail have an equivalent to Warmforge for warmup?
We include warmup in the base mailbox price rather than charging for it separately. New mailboxes start warmup automatically on provisioning, ramp over 14-21 days following Gmail and Outlook conventions, and continue maintenance warmup at low volume after that. The warmup is not as feature-rich as a dedicated standalone warmup tool (Mailreach, Warmforge, Warmy, Lemwarm) but it is sufficient for the vast majority of cold email programs. If you have a deliverability incident that requires aggressive recovery warmup, you may want to add a dedicated warmup tool on top - we are honest that this is a gap relative to the Forge family's bundled approach with Warmforge.
What about Primeforge - is StackMail's Microsoft 365 support comparable?
Primeforge is the Forge family's dedicated Microsoft 365 product, separate from Mailforge's Google-leaning surface. StackMail handles both Google Workspace and Microsoft 365 in one dashboard with the same automated DNS, the same provisioning flow, and the same per-mailbox pricing. If you are running an MS365-heavy stack, you can buy StackMail mailboxes directly without adding a second product. If you are already on Primeforge, the migration shape is the same as Mailforge - export the list, provision matching StackMail capacity, warm in parallel for 14-21 days, reconnect the sequencer, cancel Primeforge.
Does StackMail have a dedicated IP or private infrastructure option like Infraforge?
Not yet at the same depth. Our default provisioning gives you isolated Google Workspace and Microsoft 365 tenants per workspace, which provides genuine blast-radius isolation - one tenant getting flagged does not affect another tenant under your account. What we do not currently offer is fully dedicated IP ranges with custom rDNS the way Infraforge does at the high end. For 90%+ of cold email programs, the standard tenant isolation is sufficient; if your sending strategy specifically requires dedicated IP, Infraforge inside the Forge family is currently the more mature option and worth the premium pricing.
Is StackMail a real Google Workspace reseller, or a reseller of a reseller?
StackMail is operated by StackMail, a registered company with direct partner agreements as a Google Workspace authorized reseller and a Microsoft Cloud Solutions Provider. We buy seats wholesale from Google and Microsoft and resell them with automation on top - same posture as Mailforge, InboxKit, Zapmail, Primeforge, and the other infrastructure companies in this category. We do not use Azure Communication Services (a transactional email API) marketed as cold email infrastructure, which is a distinct and more risky category that some newer entrants ship.
If Mailforge offers $2/mailbox at scale and StackMail offers $2.50, why not just go with Mailforge?
If pure per-mailbox cost is your only decision criterion at large scale, Mailforge's annual-commitment math is genuinely competitive and you should use it - we will not pretend otherwise. The reason most StackMail customers come from Mailforge or evaluate both is that pure per-mailbox cost is rarely the only criterion. The other variables are: how often do you switch sequencers (StackMail wins on neutrality), how often do you need free standalone deliverability tools (StackMail's free tool suite is a real workflow advantage), and do you want a single-purpose vendor versus a five-product family in your billing (this is a personal preference). At equal per-mailbox cost the choice is about ecosystem fit; at $0.50/mailbox cheaper Mailforge has a small raw-cost edge that may or may not matter depending on the rest.
How fast can I get StackMail mailboxes after signing up?
10-20 minutes for the first cohort of mailboxes, identical to Mailforge's provisioning speed. The flow is: pick a plan, choose or buy a domain, our automation creates the Google Workspace or Microsoft 365 tenant, configures DNS, creates the mailboxes, and starts warmup. You will see live mailboxes in the dashboard inside 20 minutes. Warmup then runs 14-21 days before the mailboxes are ready for production cold email volume - that timeline is identical across all providers because it is set by Gmail and Outlook deliverability heuristics, not by the provider's automation.
Ready to move?
Provision Google Workspace and Microsoft 365 mailboxes in minutes with automated SPF, DKIM, and DMARC. From $2.50/mailbox on annual billing.