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

I have set up cold email infrastructure on shared SMTP pools, on dedicated IPs, and on real Google and Microsoft mailboxes. These three tools sit in three different camps, so this is not an apples-to-apples race on price. It is a question of what kind of mailbox you are actually buying.

Maildoso leans on cheap proprietary SMTP inboxes. Inframail gives you unlimited Microsoft inboxes on a dedicated IP for one flat fee. Primeforge gives you real Google Workspace and Microsoft 365 mailboxes tuned for cold outreach. If you want the full picture before you commit, my cold email infrastructure setup guide walks through the moving parts.

Cold Email Infrastructure Comparison at a Glance: Maildoso vs Inframail

Here is the short version before the detail. Every cell is a fact you can check on each vendor's live site.

Maildoso Overview: Features, Pricing, and Limitations

Maildoso is a cold email infrastructure provider founded in 2023 and based in California. Its pitch is simple: cheap inboxes, fast setup, and one dashboard for both proprietary SMTP and Google Workspace mailboxes. Most of its low headline prices come from its own SMTP infrastructure rather than real mailbox licenses.

Core features I would highlight:

• Proprietary SMTP mailboxes: cheap inboxes on Maildoso infrastructure, with Google Workspace available at a higher rate.
• Rotating IP pool: emails send across many IPs, and a flagged IP is swapped for a clean one automatically.
• Self-healing mailboxes: weak or burned inboxes are pulled from rotation to protect active accounts.
• CAPTCHA domain protection: hides your primary domain to keep it off blacklists.
• Built-in monitoring: a per-mailbox health score and inbox placement tests every three days.
• Automated DNS and API: SPF, DKIM, and DMARC set up for you, plus API and MCP access.

Pricing. On the live maildoso.ai pricing page, monthly SMTP plans run $75/mo for 30 mailboxes ($2.50 each), $255/mo for 300 ($0.75 each), and $499/mo for 1,000 ($0.50 each). Legacy quarterly plans bundle domains: 32 mailboxes plus 8 domains at $299/quarter (about $99/mo). Domains are free on quarterly plans only, otherwise about $12 a year, and Maildoso runs a no-discount policy. Warm-up is a separate add-on starting at $160/mo and works only with Gmail and Outlook.

Who it fits. Cost-conscious agencies and operators who want the lowest possible price per mailbox and already run their own warm-up and monitoring.

What reviewers say

Maildoso carries a 4.6 to 4.8 rating on G2 across more than a hundred reviews, and setup speed is praised consistently. The recurring complaint is deliverability variability on the shared pool. In late 2025 Maildoso had a network-wide blacklist event: users on r/coldemail reported the IP pool and domains listed on SURBL, and verified G2 reviewers described every domain getting burned in a single day and replaced with spammy .click, .top, and .xyz domains. The founder compensated affected users, but reviewers noted that communication during the incident was slow while active campaigns stalled.

Inframail Overview: Features, Pricing, and Limitations

Inframail calls itself the first automated email infrastructure setup platform. It runs on Microsoft's cloud with dedicated US IPs, and its headline idea is flat-rate pricing: unlimited inboxes for one monthly fee, no per-mailbox charge.

Core features worth noting:

• Unlimited Microsoft inboxes: create as many inboxes as you want at a flat price, with no per-inbox fee.
• Dedicated US IP: one IP on the Unlimited plan, three on the Agency Pack, so your reputation is isolated.
• Automated DNS: SPF, DKIM, and DMARC configured in roughly two to three minutes.
• Phantom redirect: hides domain redirects from email providers to reduce spam placement.
• Deliverability dashboard: IP and domain health monitoring with auto-delisting at a claimed 68.3% success rate.
• Sequencer export: buy domains in-app and export to Instantly, Smartlead, or Reachinbox.

Pricing. On the live inframail.io site, the Unlimited Plan is $129/mo with one dedicated US IP, unlimited inboxes, 10 free domains, and a cap of 80,000 emails per month. The Agency Pack is $327/mo with three dedicated IPs and a 300,000 email cap. A done-for-you plan runs $499/mo (or $3,497 once) and is the only tier that bundles warm-up. Annual billing takes 30% off, so the Unlimited plan works out to roughly $90/mo annual ($129 x 0.70).

Who it fits. Agencies that want predictable, flat-rate Microsoft infrastructure on a dedicated IP and whose monthly send volume fits comfortably under the cap.

What reviewers say

Inframail's reviews are strongly positive, with a 4.8 out of 5 Trustpilot score and praise for fast setup and responsive support. The honest trade-offs sit in the fine print rather than in bad reviews. As independent comparisons note, the "unlimited inboxes" plans still cap monthly send volume at 80,000 and 300,000 emails, the infrastructure is Microsoft-only with no Google Workspace option, and warm-up is bundled only in the $499 done-for-you plan, so standard plans need an external warm-up tool. It is also a newer, smaller provider than the more established names.

Primeforge Overview: Real Google and Microsoft Mailboxes for Cold Email

Primeforge provisions real Google Workspace and Microsoft 365 mailboxes built specifically for cold outreach. These are legitimate mailboxes with US IP addresses, not EDU tricks or fragile loopholes, and they are ready to send in about 30 minutes. Primeforge is the Google and Microsoft mailbox layer of the Forge Stack.

Core features I lean on:

• Real Google Workspace + Microsoft 365: genuine mailboxes with a business license, not resold or repurposed accounts.
• ESP matching: send from the same provider your prospect uses to boost primary-inbox placement.
• US-based IPs: better trust and placement when targeting US recipients.
• Automated DNS: SPF, DKIM, DMARC, and custom tracking configured for every domain.
• Bulk DNS management: update records across many domains in a few clicks.
• Mailbox profile pictures and GIFs: added at scale to make outreach look legitimate.
• Multiple workspaces: organize domains and inboxes by client, campaign, or team.
• Tool-agnostic: works with any sending software, including Salesforge.

The Forge Stack context. Primeforge is one of three infrastructure options in the Forge Stack: Primeforge for Google and Microsoft mailboxes, Mailforge for shared infrastructure, and Infraforge for private dedicated IPs. Warm-up runs through Warmforge, leads come from Leadsforge, and Salesforge handles multi-channel sending with Agent Frank as an optional AI SDR. The pieces sync natively, which is why I usually recommend you diversify your cold email infrastructure across two providers.

Pricing. Primeforge is $4.50 down to $3.50 per mailbox per month depending on volume. There are no separate plan tiers and no send cap on the platform itself. You can verify current Primeforge pricing on the live site. Warm-up and placement testing run through Warmforge, which is included free and unlimited with a Salesforge subscription.

Who it fits. The Forge Stack is built for B2B teams selling at ACVs of $5,000 to $100,000 into startups, SMBs, and mid-market companies, targeting thousands of businesses. Primeforge fits best when your prospects sit on Google Workspace or Microsoft 365 and primary-inbox placement decides whether you book the meeting.

Honest limitations. Primeforge is infrastructure, so you still need a sequencer and a warm-up product alongside it. Placement testing lives in Warmforge rather than inside Primeforge, billing for warm-up and monitoring is separate, and there is no self-serve free trial. If you only want disposable SMTP volume at the lowest possible price and do not care whether the mailboxes are real Google or Microsoft accounts, Primeforge is not the cheapest line item.

See Salesforge
in Action

Start Live Demo Now

Head-to-Head Feature Comparison: Maildoso vs Inframail

One axis dominates this comparison, but it is not the only one that matters. Here is the full breadth.

Mailbox type and legitimacy

This is the core split. Primeforge gives you real Google Workspace and Microsoft 365 mailboxes with a business license. Maildoso's cheap inboxes are proprietary SMTP on its own infrastructure, with real Google Workspace available only at a higher price. Inframail provisions Microsoft inboxes on its dedicated IPs. If you need genuine Google mailboxes specifically, Maildoso charges more for them and Inframail does not offer Google at all. For ESP matching against Google prospects, real Google mailboxes are the deciding factor.

Email deliverability and warm-up

Primeforge leans on ESP matching and US IPs, and warm-up runs through Warmforge with placement testing. Maildoso sends from a shared, rotating IP pool, so your deliverability partly depends on other senders; its late-2025 SURBL blacklist event is the clearest example of that shared risk, and its warm-up add-on starts at $160/mo. Inframail isolates reputation on a dedicated IP and monitors blacklists, but its standard plans do not bundle warm-up, so you bring an external tool. My diversification guide explains why I never run a single pool.

Setup, DNS, and management

All three automate SPF, DKIM, and DMARC. Inframail is fastest at two to three minutes, Maildoso around ten, and Primeforge about thirty because it provisions real Google and Microsoft accounts. Primeforge adds bulk DNS updates, multiple workspaces, and mailbox profile pictures and GIFs at scale. If you want to understand what is being configured under the hood, my DNS setup checklist covers every record.

Pricing and scalability

The models scale very differently. Maildoso is cheapest per mailbox at high volume, dropping to about $0.50 a mailbox at 1,000. Inframail is flat at $129/mo for unlimited inboxes, which is very low per inbox once you pass roughly 40 mailboxes, though the 80,000 email monthly cap is the real ceiling. Primeforge charges $3.50 to $4.50 per mailbox with no send cap, so cost tracks the number of real mailboxes you run.

Integrations and the Forge Stack

All three are tool-agnostic and export to common sequencers. The difference is the stack around them. Primeforge plugs natively into Salesforge, Mailforge, Infraforge, Warmforge, and Leadsforge, so infrastructure, warm-up, leads, and sending share one system. Maildoso and Inframail are standalone infrastructure that you wire to a separate sequencer yourself. For a wider view, see my roundup of cold email infrastructure tools.

Compliance and control

Primeforge is SOC 2 compliant and gives you full ownership of real Google and Microsoft mailboxes. Inframail publishes a DPA and isolates you on a dedicated IP. Maildoso's control comes from IP rotation and CAPTCHA domain masking, but the shared pool means your reputation is never fully your own. If isolation and owning genuine mailboxes matter for client work, that favors dedicated or real-mailbox setups over a shared pool.

Pricing Comparison: Primeforge vs Maildoso vs Inframail

Headline prices hide the real cost, because each tool charges for a different thing. Here is the like-for-like view.

A real scenario. Say you need about 50 mailboxes across 15 to 20 domains, sending to Google and Outlook prospects. On Primeforge that is roughly $175 to $225 a month for 50 real mailboxes, plus domains. On Maildoso the monthly SMTP tiers jump from 30 ($75) to 300 ($255), so 50 mailboxes means paying for the 300 tier or using the legacy quarterly 68-mailbox plan at $499 a quarter (about $166/mo), plus warm-up if you add it. On Inframail you pay one flat $129/mo for unlimited inboxes on a single dedicated IP, as long as you stay under the 80,000 email monthly cap, plus an external warm-up tool.

The takeaway: Maildoso has the lowest raw price, Inframail offers flat, predictable billing under its send cap, and Primeforge costs a little more to put you on real Google and Microsoft mailboxes with ESP matching.

Who Should Use Which Cold Email Infrastructure

You might consider Maildoso if:

• You want the lowest possible cost per mailbox and are comfortable on a shared, rotating-IP SMTP pool.
• You already run your own warm-up and monitoring and do not need real Google or Microsoft mailboxes.
• You send high volume where cents per mailbox move your margins.

You might consider Inframail if:

• You want a flat monthly fee with unlimited Microsoft inboxes on a dedicated IP.
• Your monthly send volume fits under the 80,000 email cap on the Unlimited plan.
• You already have a warm-up tool wired into your sequencer.

Choose Primeforge if:

• Your prospects are on Google Workspace or Microsoft 365 and ESP matching decides your inbox placement.
• You want real, owned mailboxes with US IPs and automated DNS, ready in about 30 minutes.
• You are a B2B team at $5,000 to $100,000 ACVs targeting thousands of accounts.
• You run agency or multi-client work and want workspaces plus bulk DNS management.
• You want infrastructure that plugs natively into Warmforge, Salesforge, and the rest of the Forge Stack.

Not sure which mailbox type fits your motion? My guide on how to choose a mailbox provider for cold outreach is the place to start.

Final Verdict: Which Cold Email Infrastructure to Choose

Maildoso and Inframail are both solid budget infrastructure for the right operator. Maildoso is cheap proprietary SMTP on a shared, rotating pool. Inframail is unlimited Microsoft inboxes on a dedicated IP, capped by send volume. Neither gives you real, verified Google Workspace and Microsoft 365 mailboxes, and that is the difference that decides primary-inbox placement against Google and Outlook prospects.

For cold outreach where inbox placement is the whole game, Primeforge is the stronger choice. At $3.50 to $4.50 per real mailbox with US IPs, automated DNS, ESP matching, and no platform send cap, it is built for deliverability rather than rock-bottom price.

One falsifiable benchmark: in the public J-Reach case study, the team ran 69 Primeforge mailboxes across 23 domains and reported zero mailbox failures over more than six months of continuous sending. You can read the full Primeforge deliverability results too.

Frequently Asked Questions

Is Primeforge better than Maildoso and Inframail?

For cold outreach that depends on primary-inbox placement, Primeforge is the stronger choice because it gives you real Google Workspace and Microsoft 365 mailboxes with ESP matching and US IPs. Maildoso is cheaper on proprietary SMTP, and Inframail offers flat-rate unlimited Microsoft inboxes on a dedicated IP. The right pick depends on whether you need real Google and Microsoft mailboxes or the lowest possible price per inbox.

What is the main difference between Primeforge, Maildoso, and Inframail?

It comes down to mailbox type. Primeforge provisions real Google Workspace and Microsoft 365 mailboxes. Maildoso's low-cost inboxes are proprietary SMTP on a shared, rotating IP pool, with Google Workspace available at a higher price. Inframail provisions Microsoft inboxes on a dedicated IP with a flat fee but a monthly send cap of 80,000 emails on its entry plan.

Which is cheaper: Primeforge, Maildoso, or Inframail?

Maildoso is cheapest per mailbox, from $2.50 each at 30 mailboxes down to about $0.50 at 1,000. Inframail is flat at $129/mo for unlimited inboxes, which is very low per inbox at scale but capped at 80,000 emails a month. Primeforge runs $3.50 to $4.50 per real mailbox with no send cap, so it costs more for genuine Google and Microsoft mailboxes.

Do Maildoso and Inframail use real Google Workspace mailboxes?

Not by default. Maildoso's cheap inboxes are proprietary SMTP on its own infrastructure, and real Google Workspace is available only at a higher price tier. Inframail uses Microsoft-based infrastructure and does not offer Google Workspace at all. Primeforge is the option here that provisions genuine Google Workspace and Microsoft 365 mailboxes with a business license, which matters for ESP matching.

Can I switch from Maildoso or Inframail to Primeforge easily?

Yes. Primeforge is tool-agnostic, so it works with whatever sequencer you already use, including Instantly, Smartlead, or Salesforge. You buy new domains and mailboxes in Primeforge, let it configure SPF, DKIM, and DMARC automatically, run a two-week warm-up through Warmforge, then point your existing campaigns at the new inboxes. Mailboxes are ready in about 30 minutes.

Which has better email deliverability for cold outreach?

Primeforge is built around deliverability with real Google and Microsoft mailboxes, US IPs, and ESP matching, which sends from the same provider your prospect uses. Maildoso relies on a shared, rotating IP pool, which carries cross-contamination risk, shown by its late-2025 SURBL blacklist event. Inframail isolates you on a dedicated IP, which protects reputation but needs an external warm-up tool on standard plans.

Does Primeforge include email warm-up?

Warm-up is not built into Primeforge itself. It runs through Warmforge, the Forge Stack deliverability product, which is included free and unlimited with a Salesforge subscription and works with Primeforge mailboxes. A two-week warm-up before sending is the standard recommendation. Maildoso charges a warm-up add-on from $160/mo, and Inframail bundles warm-up only in its $499 done-for-you plan.

Who is Maildoso best for, and who is Inframail best for?

Maildoso fits cost-conscious operators who want the lowest price per mailbox on proprietary SMTP and run their own warm-up. Inframail fits agencies that want flat-rate, unlimited Microsoft inboxes on a dedicated IP and whose monthly volume stays under the send cap. Primeforge fits teams whose prospects are on Google or Microsoft and who need real mailboxes with ESP matching for primary-inbox placement.