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

I have set up cold email infrastructure with all three of these providers at different times over the last 18 months. This is not a paid post. I run outbound for B2B SaaS clients and the choice of mailbox provider is the single decision that determines whether the next 90 days produce pipeline or scorched domains.

Mailscale, Maildoso, and Primeforge solve the same problem in three different ways. Mailscale and Maildoso both lean on shared SMTP infrastructure with cost as the headline. Primeforge sells you real Google Workspace and Microsoft 365 mailboxes that send from US IPs and behave like the mailboxes your prospects already trust.

The trade-offs are not obvious until you scale. Below I compare the three on mailbox type, deliverability, pricing transparency, and what happens when a campaign starts burning. Every figure is sourced from the live vendor pricing pages as of May 2026 and from public case studies and Trustpilot reviews.

Quick-glance comparison

Mailscale overview

Mailscale is a cold email mailbox provider founded in late 2023 by Yassin Baum and Mo. The product is SMTP-only: Mailscale runs its own SMTP servers and IP pools and sells you mailboxes that plug into Instantly, Smartlead, Apollo, Lemlist, Reply.io, or any sender that supports IMAP/SMTP. There are no real Google Workspace mailboxes and no real Microsoft 365 mailboxes.

The product positioning is speed and cost. Mailscale claims 50 inboxes in under 60 seconds and prices that undercut Google Workspace by roughly 80% at scale.

Core features

• SMTP mailboxes on shared infrastructure with automated DNS (SPF, DKIM, DMARC)
• Domain purchase inside Mailscale at $10 to $15 per .com per year, or bring your own at $2/domain
• "Deliverability guarantee" with domain replacement if inbox placement drops below 80% within 30 days
• Plug-and-play with Instantly, Smartlead, Apollo, Lemlist, Reply.io, Mailshake
• Recommended sending volume of 30 to 50 emails per mailbox per day
• Cold email training course bundled with the Business plan

Pricing

Mailscale does not publish the price tiers on the public homepage. The site routes you to a demo booking form where you have to fill in your full name, email, website, current cold email volume, and last month's revenue before anyone shows you a number. The plans behind that form are Solopreneur at $79/mo for 15 inboxes ($5.27/inbox), Business at $119/mo for 50 inboxes ($2.38/inbox), Enterprise at $249/mo for 200 inboxes ($1.25/inbox), and Unlimited Mailboxes at $1,000+/mo for high-volume senders.

A 7-day free trial is advertised on the pricing tabs. The Refund Policy page states Mailscale operates a strict no-refund policy once mailboxes are provisioned.

Who Mailscale fits

Solo founders and small operators running a single cold email motion who want a fast SMTP setup and accept shared IP infrastructure as the trade-off for $1.25 to $5 per inbox.

Honest observations

• SMTP-only means you cannot run ESP-matching strategies that send Gmail-to-Gmail and Outlook-to-Outlook
• The Trustpilot score sits at 4.1 over 88 reviews. One April 2026 1-star review documents a $1,140 annual auto-renewal with a cancellation flow the reviewer describes as broken at every exit route
• Pricing is not on the public site. You hand over five fields of personal data before you see what the product costs
• The "deliverability guarantee" only applies when you buy domains through Mailscale. Bring your own domains and the guarantee is voided

Maildoso overview

Maildoso is a cold email infrastructure provider founded in August 2023 by Nikita Bykadarov, based in Granite Bay, California. The core product is shared SMTP mailboxes with IP rotation, with optional real Google Workspace mailboxes sold in bundles at higher tiers. Maildoso reports 10M+ emails sent per day and 400K+ mailboxes managed across their customer base.

The pitch is shared SMTP at the cheapest per-mailbox price in the market, with self-healing mailbox technology that pauses burned mailboxes for 14 days before rotating them back in.

Core features

• SMTP mailboxes on shared IPs with automatic rotation across hundreds of IPs
• Optional real Google Workspace mailboxes from $2.50 in bundles, marketed as for B2C-style inboxes
• Self-healing mailbox tech that pauses suspended mailboxes for 14 days then restores them
• Inbox placement tests every three days with mailbox health scores
• Master inbox to manage replies across all sending domains
• Custom tracking domains and domain masking via captcha
• Recommended sending volume of 15 cold emails per SMTP mailbox per day

Pricing

Maildoso publishes pricing openly. Monthly SMTP plans run $75 for 30 mailboxes ($2.50/mailbox), $158 for 70 mailboxes ($2.25/mailbox, -11%), and $570 for 300 mailboxes ($1.90/mailbox, -31%). Quarterly SMTP plans run $299 for 32 mailboxes ($3.10/mailbox), $499 for 68 mailboxes ($2.40/mailbox), and $2,199 for 400 mailboxes ($1.80/mailbox).

The Combo plans bundle SMTP and Google Workspace mailboxes at $90 for 15+15, $175 for 35+35, or $675 for 150+150. Quarterly plans include free domains; monthly plans do not. Domains are $12/year if you need them. There is a 30-day money-back guarantee.

Who Maildoso fits

Agencies and teams sending high-volume cold email who want the lowest per-mailbox SMTP cost on the market and accept shared IP infrastructure as the trade-off.

Honest observations

• SMTP is shared infrastructure. A 100-mailbox third-party test on Reddit reported 12 of 70 SMTP mailboxes hit spam at weeks 7-8, with support rotating them to clean IPs within days. That recovery happens at the cost of your active sending schedule
• The G2 score sits at 4.6 across 163 reviews. Documented G2 review patterns flag deliverability volatility on shared IPs at scale, with one Reddit poster summarizing it as "emails get burnt out in a week"
• Real Google Workspace is an optional bundle, not the base product. The $1.80 entry price refers to SMTP, not Google Workspace
• Replacement domain quality varies. Some users on Reddit and G2 report receiving .xyz or .click TLDs as replacements instead of .com, which damages cold email credibility
• Monthly plans require separate domain purchases. The cheap quarterly plans bundle them, but you commit three months up front

Primeforge overview

Primeforge is the Google Workspace and Microsoft 365 mailbox infrastructure inside the Forge Stack. Where Mailscale and Maildoso lean on shared SMTP as the base product, Primeforge sells you real Google Workspace and real Microsoft 365 mailboxes configured for cold outreach. The mailboxes come with US-based IP addresses, profile pictures and GIFs, and full automated DNS setup. No EDU loopholes. No reseller workarounds. Just legitimate Google and Microsoft mailboxes ready in 30 minutes.

Primeforge is one product inside the broader Forge Stack alongside Mailforge (shared IP infrastructure), Infraforge (private dedicated IPs), Warmforge (deliverability and warm-up), Leadsforge (lead search engine), and Salesforge (the outreach platform). The recommended setup is mixing Primeforge with either Mailforge or Infraforge so you always have a mailbox provider matching your prospect's ESP.

Core features

• Real Google Workspace and real Microsoft 365 mailboxes (not EDU tricks, not reseller hacks)
• US-based IP addresses on every mailbox
• Automated DNS setup for SPF, DKIM, DMARC, and custom tracking domains
• Pre-warmed mailboxes available for senders who need to start day one
• Mailbox profile pictures and GIFs configured at scale
• 30-minute setup from signup to first send
• Bulk DNS updates across hundreds of domains
• Multiple workspaces (one workspace per client for agencies)
• Primeforge API for programmatic mailbox management
• Integrates natively with Salesforge, Warmforge, and any sending tool
• SOC 2 compliant infrastructure

The Forge Stack context

Primeforge is the ESP-matched layer of a unified infrastructure stack. The Salesforge team recommends combining Primeforge with Mailforge (shared IPs at $2 to $3/mailbox) or Infraforge (private dedicated IPs at $3 to $4/mailbox) because the most resilient outbound setups use 2 or more ESPs. The pattern reduces the risk of infrastructure burn and matches the prospect's mailbox provider on the way in.

Pricing

Primeforge prices Google Workspace and Microsoft 365 mailbox slots at $4.50/mailbox monthly or $3.50/mailbox annual (annual gives you 2 months free). Domains are $14/year for .com. The interactive pricing calculator on the Primeforge pricing page shows the exact monthly and annual cost for any combination of sequence length, mailboxes per domain, and contacts processed per month.

An example from the calculator: 25 mailboxes across 9 .com domains costs $94/month billed annually or $113/month billed monthly, plus $126 in one-time domain registrations for the year.

The subscription includes the automated DNS setup, inbox hosting, maintenance, and Primeforge API access. Mailbox slots let you delete and recreate mailboxes without extra charges (you pay for slots, not active mailbox counts).

Who Primeforge fits

B2B teams, agencies, and high-volume senders running cold outreach where deliverability is the budget item. Specifically: teams that want to send Gmail-to-Gmail and Outlook-to-Outlook (ESP matching), teams handling 30 to 200 mailboxes across 10 to 70 domains, and agencies running multi-client outbound where each client needs isolated infrastructure.

Real customer proof

J-Reach, the LinkedIn cold outreach training company, runs 23 domains and 69 mailboxes on Primeforge. Per the published J-Reach case study, they have maintained six months of continuous use with zero bounce issues and zero mailbox failures. Quote from CEO Yap Junte: "After two weeks of warm-up, I've never had any issues with bouncing or mailboxes dying out of nowhere for the last six months using it."

Honest observations

• Primeforge does not offer a free trial. It is an infrastructure product, not a SaaS app. You buy slots and domains
• Each Forge product is a separate subscription. There is no single bill across Primeforge, Mailforge, Infraforge, and Warmforge
• Per-mailbox price is higher than Maildoso or Mailscale Enterprise. You pay for the legitimacy of real Google and Microsoft mailboxes, not just SMTP credentials
• The recommended hybrid setup (Primeforge + Mailforge or Infraforge) means budgeting for two infrastructure subscriptions if you want maximum resilience

Head-to-head feature comparison

Mailbox type and ESP authenticity

This is the single biggest difference between the three. Mailscale sells SMTP mailboxes only. Maildoso sells shared SMTP as the base product with optional Google Workspace bundles at higher tiers. Primeforge sells real Google Workspace and real Microsoft 365 mailboxes as the default product.

The practical effect: when your prospect is on Gmail, a real Google Workspace mailbox is the same ESP. When they are on Outlook, a real MS365 mailbox is the same ESP. ESP-matched sending lands more reliably in the primary inbox because the receiving filter sees a known peer, not an SMTP server with an unfamiliar IP. Mailscale cannot do this at all. Maildoso can, but only if you upgrade to the Combo or Google Workspace plans at $2.50 to $3.00 per Google Workspace mailbox.

Deliverability and warm-up infrastructure

Mailscale runs shared SMTP servers and shared IP pools. They publish a "95-100% deliverability guarantee" but the fine print restricts that guarantee to mailboxes on domains purchased through Mailscale. Their public stance: "Deliverability nowadays isn't a function of infrastructure or mailboxes anymore. It's about staying under Google and Outlook's radar."

Maildoso uses shared SMTP with IP rotation across hundreds of IPs and a self-healing mechanism that pauses burned mailboxes for 14 days. Inbox placement tests run every three days. Documented Reddit and G2 test data shows 12 of 70 SMTP mailboxes hitting spam at weeks 7-8 in one 100-mailbox test, with support rotating them to new IPs.

Primeforge ships real Google Workspace and MS365 mailboxes with no shared IP pool. Warm-up is handled natively through Warmforge (the Forge Stack deliverability product), which is a separate subscription but is included free with any Salesforge subscription. The J-Reach data point speaks for itself: 23 domains, 69 mailboxes, six months, zero failures.

Pricing transparency and trial structure

Maildoso publishes all pricing on the pricing page with a 30-day money-back guarantee. Primeforge publishes all pricing on the pricing page with an interactive calculator and no free trial (you buy slots).

Mailscale gates pricing behind a demo booking form that requires your full name, email, website URL, current cold email volume, and prior month's revenue. After you book the demo and (presumably) see pricing, the refund policy is "no refunds once mailboxes are provisioned." The 7-day free trial sits inside the pricing tabs that only render after you complete the demo flow.

Scale, ownership, and infrastructure burn

SMTP infrastructure is inherently shared. On Mailscale and Maildoso, your sender reputation is partly determined by your IP neighbors. A spammer joining the same pool can drag down placement across the entire pool. Maildoso documents this risk openly: their self-healing mechanism exists because shared SMTP burns predictably under load.

Primeforge mailboxes are real Google and Microsoft accounts on US IPs assigned by Google and Microsoft. Reputation moves with the mailbox, not the pool. If you need to scale to thousands of mailboxes with full IP control, the Forge Stack recommendation is to layer in Infraforge (private dedicated IPs) alongside Primeforge.

Forge Stack integration and extensibility

Mailscale integrates with any sender that accepts SMTP credentials (Instantly, Smartlead, Apollo, Lemlist, Reply.io). It does not run sequences itself. Maildoso has the same integration model with developer API access and a documented integrations library.

Primeforge integrates natively with Salesforge for outreach sequences, Warmforge for deliverability monitoring, and the Forge CLI / MCP server for programmatic control. A complete cold email workflow runs across one unified stack: Leadsforge finds the contacts, Primeforge hosts the mailboxes, Warmforge keeps them warm, and Salesforge sends the sequences. Switching costs are lower because nothing is duct-taped through Zapier between products.

Compliance and trust signals

Primeforge is SOC 2 compliant, with the badge on every page across the Forge Stack subdomains. Salesforge maintains a Trust Center at trust.salesforge.ai. Neither Mailscale nor Maildoso advertises SOC 2 compliance on their public sites or pricing pages.

For B2B teams selling into regulated buyers (financial services, healthcare, mid-market enterprise procurement), SOC 2 matters at the procurement diligence stage. The compliance gap is a quiet differentiator that does not surface until your buyer's security team starts asking questions.

Pricing comparison

The headline math at 50 mailboxes: Mailscale Business at $119/mo, Maildoso SMTP at $158/mo for 70, Primeforge at roughly $175/mo annual for 50 real Google Workspace mailboxes. Mailscale is the cheapest per inbox at this tier, but you are paying for SMTP credentials, not for the Gmail brand that lands in the primary inbox.

At 200 mailboxes: Mailscale Enterprise at $249/mo ($1.25/inbox SMTP), Maildoso Monthly SMTP at roughly $400/mo extrapolated, Primeforge at roughly $700/mo annual for 200 real Google Workspace mailboxes. The Primeforge premium at scale is the cost of running ESP-matched sending instead of shared SMTP.

A practical scenario: an agency sending 10,000 cold emails per day across 50 client mailboxes. On Mailscale Business that runs $119/mo plus domains. On Maildoso 70-mailbox SMTP that runs $158/mo plus monthly domain costs. On Primeforge that runs $175/mo annual for 50 real Google Workspace mailboxes plus $14 per domain. The $50/month delta between Maildoso and Primeforge is what buys you ESP matching, US IPs, and the J-Reach reliability profile.

Who should use which

One honest anti-fit: if you only need 1 to 5 mailboxes for non-cold-email use (transactional sending, internal communication), buy Google Workspace directly from Google. Primeforge is built specifically for cold outreach at scale, not for daily-use mailboxes.

Final verdict

Mailscale and Maildoso both sell shared SMTP at low per-mailbox prices. Mailscale hides its pricing behind a demo and operates a no-refund policy. Maildoso publishes pricing openly and offers a 30-day refund, with the trade-off being shared IPs that burn predictably at the 7-8 week mark in documented tests.

For cold email infrastructure where deliverability is the budget, Primeforge is the stronger pick. Real Google Workspace and Microsoft 365 mailboxes, US IPs, automated DNS, 30-minute setup, and a published case study showing 23 domains and 69 mailboxes running six months with zero failures at J-Reach. Pricing starts at $4.50/mailbox monthly or $3.50/mailbox annual.

The falsifiable claim: J-Reach has documented six months of zero mailbox failures and zero bounce issues on 69 Primeforge mailboxes. That case study is public, named, and dated. No equivalent third-party-documented multi-month zero-failure claim exists for Mailscale or Maildoso at comparable mailbox counts.

Frequently asked questions

It depends on what you measure. On per-mailbox SMTP price, Mailscale Enterprise ($1.25/inbox) and Maildoso quarterly ($1.80/inbox) are cheaper. On mailbox legitimacy, Primeforge ships real Google Workspace and MS365 mailboxes with US IPs, which neither competitor offers as the default product. For B2B cold email targeting Google or Microsoft inboxes, Primeforge's ESP-matched sending lands more reliably. The J-Reach case study documents six months of zero failures on 69 Primeforge mailboxes.

SMTP mailboxes are run on the provider's own servers and IP pools. They look like generic email accounts to receiving filters. Real Google Workspace mailboxes are actual Google business accounts on Google's infrastructure. When your prospect uses Gmail, a real Google Workspace mailbox is the same ESP. That ESP match boosts primary-inbox placement. Mailscale only sells SMTP. Maildoso sells SMTP as the base product. Primeforge sells real Google Workspace and Microsoft 365 by default.

Mailscale Business at $119/mo (50 SMTP inboxes) is the cheapest headline price. Maildoso 70-mailbox SMTP at $158/mo is the closest comparison since Maildoso does not have a 50-mailbox tier. Primeforge for 50 real Google Workspace mailboxes runs roughly $175/mo on annual billing or $225/mo monthly. The $50/mo delta from Maildoso to Primeforge is the cost of real Google Workspace mailboxes instead of shared SMTP.

No. Mailscale is SMTP-only. The product positioning explicitly contrasts Mailscale with Google and Outlook ("Google and Microsoft weren't built to scale cold email outreach"). If you need real Google Workspace or Microsoft 365 mailboxes for ESP matching, Primeforge is the relevant option. Maildoso offers Google Workspace mailboxes as an optional Combo bundle at $2.50/GW mailbox, but only at the higher tiers.

No. Primeforge is an infrastructure product, not a SaaS app, so you buy mailbox slots and domains directly. After signing up you can explore the app without purchasing, but to actually create mailboxes you commit to a subscription. Annual billing gives 2 months free. Mailbox slots let you delete and recreate mailboxes at no extra charge during your subscription.

Yes. Primeforge supports bringing your own domains from any registrar, so you keep the domains you already own. Update the nameservers in your current registrar to point at Primeforge, click Connect Domain inside the Primeforge app, and Primeforge handles the DNS configuration. Your existing sender data does not migrate (cold email mailboxes are not portable across providers), but warm-up via Warmforge takes 14 days before high-volume sending.

Deliverability is a function of mailbox type, IP reputation, warm-up quality, and sending behavior. Mailscale and Maildoso both run shared SMTP, so your reputation is partly determined by other senders on your shared IPs. Primeforge runs real Google Workspace and MS365 mailboxes with US IPs assigned by Google and Microsoft, so reputation moves with each mailbox. The J-Reach case study documents six months of zero failures on 69 Primeforge mailboxes. No equivalent multi-month zero-failure claim exists publicly for Mailscale or Maildoso at the same scale.

Maildoso's SMTP mailboxes work, but they are shared infrastructure. A 100-mailbox third-party test on Reddit reported 12 of 70 SMTP mailboxes hit spam at weeks 7-8, with support rotating them to clean IPs within days. Maildoso's self-healing mechanism exists because shared SMTP burns predictably under load. For high-stakes B2B outreach where you cannot afford a mid-campaign IP rotation, real Google Workspace or MS365 mailboxes from Primeforge are the more resilient option.