Zapmail vs Mailscale: Which Email Infrastructure Is The Right Choice?

I've tested a lot of cold email infrastructure providers over the last two years. The space is loud, every vendor promises "best deliverability," and most reviewers compare per-mailbox prices in a vacuum without surfacing the things that actually break campaigns: shared IP pools, DNS misconfigurations that fail months in, support that disappears when you need it, and tier breakpoints that punish growth.

This is a head-to-head on the three I get asked about most: Infraforge, Zapmail, and Mailscale. The first is dedicated IPs and part of the broader Forge Stack. The second resells Google Workspace and Microsoft 365 inboxes. The third self-hosts SMTP with a deliverability guarantee. They are not the same product category, and the differences matter once you scale past 50 mailboxes.

Quick-glance comparison

Zapmail overview

Zapmail is a cold email infrastructure platform that provisions Google Workspace and Microsoft 365 mailboxes for outbound campaigns. The company is owned by Outbox Labs Inc., reports 1M+ mailboxes set up and 330K+ domains managed, and positions itself on workspace-level isolation - one domain per workspace, separate sender reputation per workspace.

Core features include automated DNS configuration (SPF, DKIM, DMARC), pre-warmed mailbox options, US/EU IP addresses, OAuth-based connections to 50+ outreach tools (Instantly, Smartlead, Reply, Lemlist, ReachInbox), and an Aged Domains marketplace.

Zapmail pricing

Zapmail prices monthly: Starter $39/mo (10 Google mailboxes, $3.50 per additional), Growth $99/mo (30 mailboxes, $3.25 per additional), Pro $299/mo (100 mailboxes, $3.00 per additional, API access). Annual billing offers 2 months free, bringing entry rates to roughly $2.50/mailbox. Microsoft 365 mailboxes and pre-warmed mailboxes are sold separately. Domains start at $13/year.

Who Zapmail fits

Zapmail fits teams who specifically want Google Workspace mailboxes for cold outreach and don't want to manage Google Admin themselves. The OAuth-based integration with Instantly, Smartlead, and similar sequencers is genuinely smooth.

What Trustpilot reviewers say

Zapmail holds a 4-star rating on Trustpilot across 75+ reviews. Most reviews are positive about setup speed and support responsiveness. The 1-star reviews are worth reading before committing. A common thread: reviewers report that the marketed "US-hosted" infrastructure resolved to non-US IPs in their tests, and a Reddit thread on r/coldemail documented that Zapmail provisions some Google Workspace accounts through Reseller Club (an India-based reseller). Zapmail's founder posted a rebuttal pointing to email headers as verification.

Other 1-star reviews flag opaque referral-program terms, security concerns around how support handles customer credentials, and a strict no-refunds policy. None of this is disqualifying on its own - it's the kind of friction that surfaces at scale.

Honest limitations

• Shared admin access across the reseller infrastructure - you don't own the underlying Google billing relationship
• API access gated to the $299/mo Pro plan only
• No free trial, no money-back guarantee per the published cancellation policy
• Pre-warmed mailboxes cost extra on top of base pricing
• No unified inbox view across mailboxes

Mailscale overview

Mailscale is a cold email infrastructure platform that owns its full SMTP stack - servers, IP pools, the whole thing - rather than reselling Google or Microsoft. It markets a 95-100% deliverability guarantee during the first two weeks of warmup, with domain replacement free of charge if inbox placement drops below 80%. The company reports 3,000+ customers.

Core features include automated DNS configuration, in-platform domain purchasing ($9-15/domain/year), CSV export of inbox credentials for plugging into any IMAP/SMTP-compatible sender (Instantly, Smartlead, Apollo, Lemlist, Reply), and an included cold email course on higher tiers.

Mailscale pricing

Mailscale uses fixed tiers tied to mailbox caps. Published rates: Solopreneur $79/mo (15 inboxes, ~2K prospects/mo target), Business $119/mo (50 inboxes, ~10K prospects), Enterprise $249/mo (200 inboxes, ~30K prospects, +$1/inbox beyond cap), Unlimited Mailboxes $1,000+/mo (custom). Annual billing brings 20% off - Solopreneur drops to $63/mo, Business to $95/mo, Enterprise to $199/mo.

Domains must be purchased inside Mailscale at $9-15/year. Bring-your-own domains are charged $2/domain/month with no deliverability guarantee. A 7-day free trial requires a credit card.

Who Mailscale fits

Mailscale fits solo operators and small agencies who want a tiered SaaS package - infrastructure plus deliverability guarantee plus included training - in one bundled price. If you sit cleanly inside one of the tier caps, the per-inbox economics at scale are competitive (Enterprise annual works out to $1/inbox/month at 200 inboxes).

What Trustpilot reviewers say

Mailscale's Trustpilot score is 4 stars across 88 reviews, but the G2-vs-Trustpilot gap tells a story. G2 reviews skew toward the setup experience (fast, easy). Trustpilot captures what happens after week two. The most-cited 1-star complaints describe deliverability dropping below 50% after the first week, domains the company itself provisioned still failing DMARC months later, and support replies that take 3-5 days.

This pattern is consistent across multiple independent reviewers - it's not one angry customer. The deliverability guarantee covers the first two weeks, but the issues reviewers describe surface week three and beyond.

Honest limitations

• Shared IP pool across all SMTP customers - one bad neighbor affects everyone on the same IP
• Hard tier breakpoints - 16 inboxes jumps you from $79 to $119, 51 inboxes jumps you from $119 to $249
• Domain lock-in - you can't easily port domains out if you decide to leave
• Bring-your-own domains penalized at $2/domain/month with no deliverability guarantee
• Multiple Trustpilot reports describe cancellation friction and a Stripe portal where the cancel button is disabled
• SMTP-based connection means no native OAuth - you're using IMAP/SMTP credentials with every sender

Infraforge overview

Infraforge is private dedicated email infrastructure built specifically for cold outreach. It is one of the seven products in the Forge Stack - alongside Mailforge (shared IP infrastructure), Primeforge (Google and Microsoft mailboxes), Warmforge (deliverability and warmup), Leadsforge (500M+ lead database), and Salesforge (multi-channel outreach). Each works standalone or together.

The differentiator is reputation isolation. Every Infraforge account runs on dedicated IPs - not a shared pool. Your sender reputation depends on your sending behavior alone. The company holds a 4.9 G2 rating and lists Woodpecker, Deel, and Dreamdata among its named users.

Core features

• Dedicated IPs on every account - no shared pool, no reputation contamination from other senders
• Automated DNS setup for SPF, DKIM, DMARC on every domain following industry best practices
• Pre-warmed domains and mailboxes available so you can send from day one instead of waiting two weeks
• Masterbox - view all emails across all accounts within a workspace in one place ($7-9/workspace/month add-on)
• Bulk DNS updates across hundreds of domains from one dashboard
• SSL and Domain Masking ($2/domain/month) to display branded websites without revealing your primary domain
• Multi-IP provisioning at $99/IP/month for additional reputation isolation
• Infraforge API for programmatic scale - included in all plans
• Multiple workspaces for clean separation between projects or clients
• Domain transferring in or out - you own the domains
• Works with any sending software - Salesforge, Instantly, Smartlead, Lemlist, anything that supports standard mailbox connections
• SOC2 compliant
• Whitelabel reseller program with 20% revenue share

The Forge Stack context

Infraforge is the infrastructure layer of the Forge Stack. The natural pairing: domains and mailboxes in Infraforge, deliverability monitoring and warmup in Warmforge, leads from Leadsforge, and sending through Salesforge. Each product works on its own, but the combination is what most of Infraforge's case studies run on.

Infraforge pricing

Infraforge prices per mailbox slot: $4/mailbox/month billed quarterly, dropping to $3/mailbox/month at annual billing or higher volumes. The annual rate reflects 2 months free. Minimum purchase is 10 mailbox slots. Domains are extra at $14/year per .com. No tier breakpoints - the price is linear with mailbox count.

Add-ons priced transparently: SSL and Domain Masking at $2/domain/month (or $6/year - the 4x annual deal), additional IPs at $99/IP/month, Masterbox at $7-9/workspace/month. Warmforge runs $0 if you use it on its own free tier, with paid options for monitoring across more mailboxes.

The pricing comparison vs Google Workspace and Microsoft 365 native: $651/month for 200 mailboxes on Infraforge vs $1,680/month on Google Workspace and $1,200/month on Microsoft 365. That's before counting the time saved on DNS setup.

Who Infraforge is best for

Infraforge fits B2B teams and agencies running high-volume cold outreach who can't afford reputation contamination from other senders. If you target 3,000+ businesses per month, manage multiple client accounts, or have hit the deliverability ceiling of shared-IP providers, dedicated IPs are the upgrade. The Woodpecker case study shows the upper end - they scaled to 2,500+ mailboxes on Infraforge.

Honest limitations

• No free trial - you need to purchase domains and mailboxes to test the infrastructure (you can sign up and explore the app for free)
• Higher per-mailbox cost than shared-IP options like Mailforge ($2-3/mailbox/month) - the trade-off is reputation isolation
• Each Forge product requires its own subscription - there's no single "Forge Stack" bill
• Dedicated IPs are powerful but require you to follow deliverability best practices; high spam-complaint volume on dedicated IPs hurts you more, not less

Head-to-head: feature by feature

IP infrastructure and reputation

This is the most important axis and the one most reviewers skip. Infraforge runs every account on dedicated IPs. Your reputation is yours. Mailscale shares IPs across customers on its self-hosted SMTP stack - the 1-star Trustpilot reviews documenting DMARC failures and sub-50% inbox placement after week one are downstream of that model. Zapmail shares Google Workspace admin infrastructure across customers within its reseller agreement, with workspace-level isolation as its mitigation.

For high-volume senders, reputation isolation is the entire game. Shared infrastructure means another customer's bad campaign can drag your sending reputation down even when your own behavior is clean.

Setup speed and DNS automation

All three offer automated DNS setup (SPF, DKIM, DMARC). All three claim 5-10 minute setup. The execution quality is where they diverge. Infraforge follows industry best practices on every domain provisioned and has documented practices for bulk DNS updates across hundreds of domains. The cited Mailscale 1-star review from January 2026 describes every single domain Mailscale provisioned still failing DMARC two months later - the automation exists, but execution failed at the customer's account. Zapmail's automated DNS is generally well-reviewed for Google Workspace setups.

Warmup and deliverability monitoring

Infraforge integrates natively with Warmforge, the Forge Stack's deliverability center. Warmforge offers a premium-by-default warmup pool of real Google Workspace and Microsoft 365 mailboxes, Heat Score monitoring per mailbox, placement tests, and blacklist checks. The pool excludes external SMTP vendors by policy.

Mailscale handles warmup in-platform with its deliverability guarantee for the first two weeks. Zapmail offers pre-warmed mailboxes as a separate purchase but doesn't run continuous warmup or placement monitoring on the same dashboard.

API access and programmatic scale

Infraforge API access is included in every plan. Zapmail gates API access to its Pro plan at $299/month. Mailscale doesn't advertise public API access. If you're building any kind of internal tooling - mailbox provisioning for clients, automated rotation, monitoring dashboards - the API is the difference between a workable workflow and a manual one.

Bring-your-own domains

Infraforge supports BYO domains natively with the same DNS automation. Zapmail supports BYO domains. Mailscale charges $2/domain/month for BYO and explicitly states it can't guarantee deliverability on domains it didn't purchase - which effectively voids the deliverability guarantee for anyone bringing existing domains.

Compatibility with sending tools

All three plug into any sender that supports IMAP/SMTP or OAuth. Infraforge connects to Salesforge natively and to any third-party sender (Instantly, Smartlead, Lemlist, Reply, etc.). Zapmail connects via OAuth to 50+ outreach tools. Mailscale exports a CSV of credentials that you import into your sender of choice.

Unified inbox and reply management

Infraforge offers Masterbox, a workspace-level view of all emails across all accounts in one place ($7-9/workspace/month). For full unified inbox functionality including LinkedIn integration, the Forge Stack provides Primebox in Salesforge. Neither Zapmail nor Mailscale offers a unified inbox - you check replies in your sender or in each mailbox individually.

Compliance and trust signals

Infraforge is SOC2 compliant. The Forge Stack publishes a Trust Center at trust.salesforge.ai. Neither Zapmail nor Mailscale publicly advertises SOC2 compliance or equivalent third-party audit certifications on their pricing or homepage as of May 2026.

Whitelabel and reseller economics

This is an agency-specific axis but worth flagging. Infraforge offers a whitelabel program with 20% revenue share, custom domain, and up to 3-year reseller terms. Neither Zapmail nor Mailscale publishes a whitelabel program. For agencies running infrastructure for clients under their own brand, this is a meaningful gap.

Pricing comparison

What 50 mailboxes actually costs

Let's do the math at a realistic scale - 50 mailboxes, which is roughly what you need to send 1,000-1,500 emails per day at safe per-mailbox volumes.

• Infraforge: 50 mailboxes × $3/mo annual = $150/mo + ~17 domains at $14/year = ~$170/mo all-in
• Zapmail Growth: $99/mo includes 30 + 20 extra at $3.25 = $164/mo + domains at $13/year = ~$186/mo
• Mailscale Business: $95/mo annual covers all 50 + 10 domains at $12/year = ~$105/mo

Mailscale is cheapest at the headline level. The question is whether the shared SMTP pool and the documented deliverability issues at week three are worth the savings. The Trustpilot reviews suggest they often aren't.

What 200 mailboxes actually costs

• Infraforge: 200 mailboxes × $3/mo annual = $600/mo + ~70 domains = ~$680/mo, dedicated IPs included
• Zapmail Pro: $249/mo annual includes 100 + 100 extra at $3.00 = $549/mo + domains = ~$640/mo, API included only at this tier
• Mailscale Enterprise: $199/mo annual covers all 200 + ~40 domains = ~$235/mo, shared IPs

At 200 mailboxes the economics tighten. Mailscale Enterprise is roughly a third the price - but again, you're paying for shared SMTP infrastructure with a deliverability guarantee that covers two weeks. Infraforge and Zapmail Pro land within $50 of each other, with Infraforge offering dedicated IPs and SOC2, Zapmail offering native Google Workspace.

Who should use which tool

You might consider Zapmail if:

• You specifically need Google Workspace or Microsoft 365 mailboxes (real ones, OAuth-connected) and don't want to manage Google Admin yourself
• You're a freelancer or small agency operating at 10-30 mailboxes and the Starter or Growth plan economics work for you
• You're comfortable with reseller-model infrastructure and don't need API access at the entry tier

You might consider Mailscale if:

• You're a solo operator on a tight budget, comfortable with shared SMTP infrastructure, and your sequencer doesn't require OAuth
• You sit cleanly inside one of the tier caps (exactly 15, 50, or 200 mailboxes) so you don't pay the breakpoint penalty
• The 95-100% deliverability guarantee for the first two weeks gives you the runway you need - and you're willing to accept the post-week-two patterns the Trustpilot reviews describe

Choose Infraforge if:

• You're sending high-volume cold outreach (more than 50 mailboxes) and can't afford reputation contamination from a shared IP pool
• You're an agency managing infrastructure for multiple clients and need isolated workspaces, dedicated IPs, and a 20% revenue-share whitelabel program
• You need API access without paying $299/month to get it
• You want SOC2 compliance and a documented audit trail as part of your sending infrastructure
• You're already using or planning to use the rest of the Forge Stack - Warmforge for deliverability, Salesforge for sending, Leadsforge for prospect data - and want native integration across the stack
• You want pre-warmed mailboxes and the option to add SSL + Domain Masking, additional IPs, and Masterbox as your operation grows

Final verdict

Zapmail and Mailscale are real products with real customers, and they fit certain shapes of cold email operation. Zapmail is the choice if you specifically need Google Workspace mailboxes through a reseller model and are comfortable with the documented IP-origin and trust-center gaps. Mailscale is the choice if you want a tiered SaaS package with bundled training and accept that the deliverability guarantee covers weeks one and two but not week ten.

For high-volume cold email infrastructure with reputation isolation, Infraforge is the stronger choice. Dedicated IPs on every account, automated DNS setup in 5 minutes, API access included on every plan, SOC2 compliant, native integration with the rest of the Forge Stack, and pricing that's linear with mailbox count instead of tier breakpoints. At $3/mailbox/month on annual billing, you're paying within $50 of Zapmail Pro for materially different infrastructure.

One falsifiable benchmark from the public case study library: Woodpecker scaled to 2,500+ dedicated mailboxes on Infraforge, and ChannelCrawler achieved an 85.71% positive reply rate running Salesforge + Infraforge + Warmforge. Both case studies are linked on the Infraforge site.

Frequently asked questions

Is Infraforge better than Zapmail and Mailscale?

For high-volume cold email infrastructure that needs reputation isolation, yes. Infraforge runs every account on dedicated IPs - not a shared pool. Zapmail resells Google Workspace through a multi-tenant admin model with workspace-level isolation. Mailscale runs self-hosted SMTP with shared IPs across customers. If you're sending more than 50 mailboxes' worth of cold outreach per month, dedicated IPs are the upgrade that matters most.

What's the main difference between Infraforge, Zapmail, and Mailscale?

Three different infrastructure models. Infraforge is private dedicated-IP infrastructure built specifically for cold outreach. Zapmail is a Google Workspace and Microsoft 365 reseller with workspace-level isolation. Mailscale is self-hosted SMTP infrastructure with shared IPs and a 2-week deliverability guarantee. The choice depends on whether you want dedicated IPs (Infraforge), Google Workspace specifically (Zapmail), or the cheapest tiered SaaS option (Mailscale).

Which is cheapest at 50 mailboxes?

Mailscale Business at $95/mo annual is the cheapest headline price for 50 inboxes. Infraforge runs about $150/mo for 50 mailboxes on annual billing. Zapmail Growth runs about $164/mo. Mailscale's lower price reflects shared SMTP infrastructure - the trade-off is the deliverability patterns documented in its Trustpilot reviews after the 2-week guarantee period.

Does Infraforge have a free trial?

Infraforge does not offer a free trial because it's infrastructure - you need to purchase domains and mailbox slots to use it. You can sign up for free, explore the app, and only pay when you provision your first mailboxes. The minimum purchase is 10 mailbox slots at $4/month each on quarterly billing, or $3/month each on annual billing.

Can I switch from Zapmail or Mailscale to Infraforge easily?

Yes. Infraforge supports domain transferring in or out, so you can bring existing domains. New mailboxes need a 2-week warmup before sending campaigns - Warmforge handles this in-house. The Infraforge support team helps with migrations, and the API allows programmatic mailbox provisioning if you're moving more than a few dozen accounts.

Which has better deliverability - Infraforge, Zapmail, or Mailscale?

Dedicated IPs give you the most control over deliverability because your sender reputation depends on your sending behavior alone, not other customers' campaigns. Infraforge's dedicated-IP model + native Warmforge integration is the configuration most likely to maintain high inbox placement over months and years. Shared-IP infrastructure (Mailscale SMTP, Zapmail's reseller model) puts you at the mercy of other senders' reputation.

Does Infraforge work with Instantly, Smartlead, and Lemlist?

Yes. Infraforge mailboxes work with any sending software including Salesforge, Instantly, Smartlead, Lemlist, Reply, Apollo, and any other tool that supports standard mailbox connections. The Infraforge API allows programmatic integration with custom workflows.

Why is Infraforge more expensive per mailbox than Mailforge?

Infraforge uses dedicated IPs - each account gets its own IP address with its own reputation. Mailforge uses a shared IP pool and runs $2-3/mailbox/month as a result. Both are part of the Forge Stack, and the recommendation depends on your sending profile. Mailforge fits high-complaint-volume or experimental sending where shared infrastructure absorbs some risk. Infraforge fits anyone strictly following deliverability best practices who wants full reputation isolation.