Comparison
Jan 20, 2026
CEO and co-founder
Inframail vs Maildoso: Head-to-Head Comparison for Cold Email Agencies
Quick verdict: The core difference between Inframail and Maildoso
Factor | Inframail | Maildoso |
|---|---|---|
Pricing model | Flat-rate ($129/month unlimited) | Per-inbox ($1.90-2.75/inbox) |
IP structure | Dedicated (1-3 IPs per plan) | Shared pool |
Platform base | Microsoft cloud | Mixed infrastructure |
Setup automation | Full DNS automation | Manual/semi-automated |
Ideal user | Agencies with 50+ inboxes | Freelancers with <20 inboxes |
Contract terms | Month-to-month | Quarterly billing options |
Bottom line: Inframail was the first of the private cold email infrastructure companies, registering its domain in November 2022. We provide dedicated IP infrastructure and unlimited inboxes at a flat rate. At 300 inboxes, you'd pay $349/month with Mailscale or approximately $825/month with Maildoso, while Inframail costs $129/month for the same volume.
Maildoso works well for operators just getting started who prioritize low upfront costs over infrastructure control. However, the platform relies on a shared IP network, which creates exposure to other users' sending behavior.
Feature comparison: Flat-rate vs per-inbox models
The business model difference creates a cascading effect on your P&L as you scale.
How Inframail's flat-rate model works
You pay $129/month regardless of inbox count. Create 50 inboxes or 500 inboxes, the platform fee stays constant. Our Unlimited Plan includes 1 dedicated US-based IP, and each IP can safely handle approximately 300-400 email inboxes for optimal performance and deliverability.
This pricing structure means your infrastructure cost-per-client decreases as you add accounts. At 10 clients with 50 inboxes total, you're paying $2.58 per inbox. At 30 clients with 150 inboxes, you're paying $0.86 per inbox.
How Maildoso's per-inbox pricing works
Maildoso charges per mailbox, with prices ranging from $1.90 to $2.75 per inbox depending on volume tier. Their largest plan offers 100 domains and 400 email accounts for $2,199 per quarter (approximately $2.75 per inbox per month). This means your infrastructure bill scales linearly with client growth.
The per-inbox model works fine when you're small. But as your agency grows, costs compound in ways that squeeze margins. Adding 5 clients shouldn't mean adding $500/month to your infrastructure bill.
What this means for your margins
"So affordable that it will make your unit economics work, even for lower ticket b2b businesses like ours." - Verified user review of Inframail
If you're targeting 15-20% net margins, infrastructure spend as a percentage of billings matters. Flat-rate pricing keeps that percentage predictable. Per-inbox pricing creates a moving target that requires constant recalculation as your client roster changes.
Cost analysis: Real TCO for 50, 100, and 200 inboxes
Here's the actual math across three common agency scenarios. I've included platform fees plus amortized domain costs (approximately $12/year per domain, with 2 inboxes per domain as standard practice).
Scenario 1: 50 inboxes (small agency)
Cost component | Inframail | Maildoso |
|---|---|---|
Platform fee | $129/month | ~$137/month (50 × $2.75) |
Domain costs (25 domains) | ~$25/month amortized | ~$25/month amortized |
Monthly total | $154/month | $162/month |
Annual total | $1,848 | $1,944 |
At 50 inboxes, the platforms are roughly comparable in cost. The real difference is the IP architecture (dedicated vs shared) rather than dollars.
Scenario 2: 100 inboxes (mid-size agency)
Cost component | Inframail | Maildoso |
|---|---|---|
Platform fee | $129/month | ~$275/month (100 × $2.75) |
Domain costs (50 domains) | ~$50/month amortized | ~$50/month amortized |
Monthly total | $179/month | $325/month |
Annual total | $2,148 | $3,900 |
Annual savings with Inframail | — | $1,752 |
At 100 inboxes, Inframail's flat-rate advantage becomes clear. You're saving over $1,700/year while getting dedicated IP infrastructure instead of shared pools.
Scenario 3: 200 inboxes (scaling agency)
Cost component | Inframail | Maildoso |
|---|---|---|
Platform fee | $129/month (Unlimited Plan) | ~$550/month (200 × $2.75) |
Domain costs (100 domains) | ~$100/month amortized | ~$100/month amortized |
Monthly total | $229/month | $650/month |
Annual total | $2,748 | $7,800 |
Annual savings with Inframail | — | $5,052 |
At 200 inboxes, the math becomes dramatic. You're saving over $5,000 annually on Inframail's Unlimited Plan, which is enough to fund a part-time VA or cover warmup tools for your entire account portfolio.
The pattern is simple: Inframail's costs grow by domain count only. Maildoso's costs grow by domain count plus inbox count. At scale, that second variable destroys margin.
Deliverability deep dive: Dedicated IPs vs shared pools
This is where the architectural difference creates real business risk.
The "private lane vs carpool lane" problem
Think of shared IP pools like carpool lanes where you're affected by other drivers. One bad actor spamming gets the whole range flagged, and your client campaigns go down even though you followed every best practice.
With Inframail, you're not sharing your IP with other users. This reduces the risk of getting blacklisted due to someone else's bad practices. Your sending behavior alone determines ESP trust.
Inframail's dedicated IP approach
We provide dedicated email hosting on dedicated IPs. Each plan comes with dedicated IPs (1 IP for Unlimited Plan, 3 IPs for Agency Pack ($327/month)) to ensure your email reputation is isolated and protected. We're built on Microsoft's cloud platform with reputable IPs.
If you warm up properly, follow volume limits, and maintain list hygiene, your reputation stays clean. You're not gambling on whether someone sharing your IP decided to blast 50,000 unverified emails yesterday.
For a detailed breakdown of this concept, watch our video on Dedicated IP vs Shared IP Pools for Cold Email.
Maildoso's shared pool model
Maildoso uses IP rotation across their shared infrastructure. While rotation can help distribute risk, it also means you never fully control your sending reputation. Dedicated IP pools offer reputation isolation and control for high-volume campaigns, ensuring stable deliverability at scale.
Real deliverability numbers
Inframail scored 88% inbox rate via GMass's deliverability testing tool. We also report 9.5/10 on Mail-Tester. For context, the closer you get to 10, the better. Scores of 9-8 are considered good, with 10 being the goal.
Setup and workflow: Automating DNS vs manual configuration
The time cost of infrastructure setup often gets overlooked in TCO calculations. Hours spent in DNS panels are hours not spent on sales calls.
How Inframail automates setup
Our platform automates the traditionally manual process, including DNS configuration, email authentication (SPF, DKIM, DMARC), and mailbox creation. This makes it easier to launch outreach campaigns at scale.
The workflow looks like this:
Purchase domain: Buy through the platform or transfer existing domains
Auto-configuration: Platform automatically sets up SPF, DKIM, and DMARC records
Create inboxes: Bulk provision Microsoft email inboxes
Export credentials: Download CSV with IMAP/SMTP credentials
Import to sending platform: Upload to Instantly, Smartlead, or your tool of choice
Users report the entire process takes minutes instead of the hours typically required for manual DNS configuration across multiple domains.
For a visual walkthrough, check out How to send 1000+ Cold Emails Per Day using Inframail, which shows the setup process.
Maildoso's setup process
Maildoso's setup involves more reliance on their pre-warmed shared infrastructure. While this can reduce initial configuration time for beginners, it also means you're inheriting whatever reputation exists in the pool.
Time savings at scale
Consider the math: Setting up 50 domains manually requires logging into DNS panels, creating SPF/DKIM/DMARC records for each domain, waiting 24-48 hours for propagation, and testing with Mail-Tester. That can easily consume a full day or more of work.
"I can set-up inboxes in 5mins while saving money on Google Workspace subscriptions and benefit from great deliverability. All of my campaigns on Inframail are on a >10% reply rate." - Verified user review of Inframail
Our Ultimate Cold Email Infrastructure Guide for 2025 covers the complete setup process in detail.
Support and reliability: What happens when things break
When a client campaign crashes on Friday afternoon, support response time determines whether you spend the weekend firefighting or relaxing.
Inframail's support model
Inframail support is available from 7:00 AM to 12:00 AM PST, 7 days a week. Priority support is included with paid plans. We also offer a free AI deliverability consultant trained on winning scripts and lead scraping. As of January 2026, Inframail has 38 5-star reviews on Trustpilot, reflecting our commitment to customer service (see all reviews: https://www.trustpilot.com/review/inframail.io).
Users consistently highlight support quality in reviews:
"One of the best mailbox infra vendors I have ever used super easy and quick setup and support is practically 24/7 with at max a 2min wait to get a question answered." - Verified user review of Inframail
"I've been an Inframail customer since early 2024 and am very pleased with Kidous and his team... Their customer support is excellent. They exhibit both politeness and thoroughness, consistently following up until they resolve my concerns completely." - Verified user review of Inframail
Maildoso's support model
Maildoso offers community-based support through their Slack channel. While community support can be helpful for general questions, it may not provide the same response time guarantees for urgent deliverability issues.
The business risk calculation
For agencies billing clients $2,000-5,000/month, a deliverability crisis that goes unresolved for 48 hours can mean losing a client entirely. Direct support with defined response times reduces that risk compared to hoping a community member happens to be online when you need help.
Our Help Center provides documentation on common issues including how to tell if your campaign emails are going to spam.
What agencies achieve with Inframail infrastructure
The numbers tell the story better than feature lists. Here's what our users are booking:
Bhavesh Kumar shares his results in our 200+ Appointments Per Month interview
Jackson Williams discusses his approach in our 6 Calls Per Day case study
Daphné Barret explains her strategy in our Book 30+ Calls interview
Watch how one user landed a major deal in our $50,000 Whale Client case study
"Inframail has been absolute gold in terms of delivering a great customer experience, and allowing me to spin up cold email infrastructure at scale for my clients as easily and fast as possible." - Verified user review of Inframail
"Been using Inframail for 2+ years now... Pretty solid deliverability compared to other platforms I've used in the past." - Verified user review of Inframail
When to choose Inframail vs Maildoso
Your situation | Recommended platform |
|---|---|
<20 inboxes, testing cold email | Maildoso |
50-100 inboxes, growing agency | Inframail |
100+ inboxes, need margin protection | Inframail |
Quarterly billing acceptable | Maildoso |
Need month-to-month flexibility | Inframail |
Shared IP risk acceptable | Maildoso |
Want dedicated IP isolation | Inframail |
Choose Maildoso if:
You're just starting with cold email and have fewer than 20 inboxes
You have near-zero budget for platform fees
You're comfortable with shared IP risk
You don't mind quarterly billing commitments
You're testing cold email before scaling
Choose Inframail if:
You run an agency managing 50+ inboxes
You need to protect margins as you scale
You want dedicated IP infrastructure (reputation isolation)
You prefer month-to-month flexibility with no long-term contracts
You value direct support over community forums
You need Microsoft-backed reliability
"InfraMail makes it remarkably easy to purchase domains, configure them correctly, create inboxes, and initiate warm-up immediately. The level of automation is exceptional and clearly designed for serious operators." - Verified user review of Inframail
Migration checklist (switching from Maildoso to Inframail)
If you're ready to switch, here's the process:
Calculate current inbox count: Document all active domains and inboxes
Export domain list: Get your domain registrar login credentials ready
Sign up for Inframail: Choose Unlimited Plan ($129/month, 1 dedicated IP) or Agency Pack ($276/month, 3 dedicated IPs) based on your volume needs
Initiate domain transfer: Move domains to Inframail's management
Wait for DNS propagation: Usually 24-48 hours
Provision new inboxes: Bulk create Microsoft inboxes
Export credentials: Download CSV for your sending platform
Begin warmup: Use external warmup tool to establish reputation on new infrastructure
Migrate campaigns gradually: Move client campaigns over 2-4 weeks
For step-by-step guidance, watch the InfraMail Setup Tutorial for Cold Email.
Important note on warmup
Inframail is an email infrastructure provider, not a sending platform. You need to connect your Inframail inboxes to a cold email sending tool like Instantly.ai, Smartlead, or Reachinbox to send campaigns. Email warmup is still recommended. Use warmup tools or services to gradually ramp up sending before launching full campaigns.
Learn more about how to warm up your inboxes after migrating to Inframail.
Sign up to Inframail and get started today.
Frequently asked questions
Does Inframail include warmup?
No. Inframail provides infrastructure (domains, inboxes, dedicated IPs). You'll need a dedicated warmup tool like Instantly's warmup feature or Warmbox. This separation gives you more control over your warmup strategy.
Can I cancel Inframail anytime?
Yes. You can cancel your Inframail subscription at any time without penalties or long-term commitments. This contrasts with Maildoso's quarterly billing structure.
What sending platforms work with Inframail?
Inframail exports IMAP/SMTP credentials that work with Instantly, Smartlead, Reachinbox, and most cold email platforms. Check what email platforms work with Inframail for the full compatibility list.
How many inboxes can I safely run per IP?
Each IP can safely handle approximately 300-400 email inboxes for optimal performance. The recommended safe sending limit is 40-50 emails per inbox per day.
What's the difference between shared and dedicated IPs?
Dedicated IPs mean your sending reputation depends solely on your behavior. Shared IPs pool reputation across all users, so one bad sender can damage everyone's deliverability.
Key terminology
Dedicated IP: An IP address used exclusively by one sender. Your reputation depends only on your sending practices.
Shared IP pool: Multiple senders share the same IP addresses. Reputation is pooled, creating "bad neighbor" risk.
SPF/DKIM/DMARC: Email authentication protocols that verify sender identity and prevent spoofing. Required for inbox placement.
TCO (Total Cost of Ownership): The complete cost of a solution including platform fees, domain costs, warmup tools, and sending platform fees.
DNS propagation: The time required (24-48 hours) for domain record changes to spread across internet servers globally.
