Comparison
Jan 21, 2026
CEO and co-founder
Companies like Maildoso: 8 cold email infrastructure platforms compared
Why agencies look for Maildoso alternatives
Most agencies don't leave Maildoso because the product is broken. They leave because the economics and architecture don't support scale.
The hidden cost of shared IP pools
Maildoso uses shared IP infrastructure, which ties your sending reputation to everyone else on that IP. When one user on your shared IP sends spam or triggers high complaint rates, ESPs penalize the entire IP pool. Industry practitioners call this the "bad neighbor effect".
Here's how it plays out: you're running a campaign for a premium B2B client, hitting 78% inbox rates. Another user on your shared IP starts sending crypto promotions that trigger spam complaints. Within 48 hours, ESPs flag your IP, and your inbox rate drops to 52%. Your client sees the results tank. You didn't do anything wrong, but you're paying the price.
Dedicated IPs solve this completely. With dedicated infrastructure, your sending behavior alone determines ESP trust. No one else's campaigns can contaminate your reputation. As one Mailreef comparison video explains, dedicated servers versus shared pools represent fundamentally different risk profiles.
When per-inbox pricing breaks your margins
Per-inbox pricing seems cheap until you calculate what scaling actually costs. Based on current Maildoso pricing tiers, costs range from $1.40-$1.80 per inbox depending on volume and billing term. At 50 inboxes, that's $70-$90/month. Manageable.
But agencies don't stay at 50 inboxes. Scale to 100 inboxes and you're paying $140-$180/month. At 200 inboxes, you hit $280-$360/month for shared IP infrastructure. Meanwhile, your client revenue doesn't scale at the same rate.
Compare this to flat-rate pricing. Inframail charges $129/month whether you create 50 or 500 inboxes. The math for scaling:
Provider | Pricing Model | Cost for 50 Inboxes | Cost for 100 Inboxes | Cost for 200 Inboxes |
|---|---|---|---|---|
Inframail | Flat-rate | $129/month | $129/month | $129/month |
Maildoso | Per-inbox | $70-90/month | $140-180/month | $280-360/month |
Google Workspace | Per-inbox | $350-420/month | $700-840/month | $1,400-1,680/month |
These economics explain why agencies look beyond Maildoso. Here are the 8 strongest alternatives, ranked by fit for agencies scaling past 50 domains.
Top 8 companies like Maildoso for cold email infrastructure
1. Inframail
Best for: Agencies scaling beyond 50 domains who need flat-rate economics and dedicated IP isolation
Inframail was among the first private cold email infrastructure companies. The platform automates Microsoft email infrastructure setup. You purchase domains through the platform or migrate existing ones, and the system configures SPF, DKIM, and DMARC records automatically.
Pricing:
- Unlimited Plan: $129/month for 1 dedicated US-based IP and unlimited inboxes
- Agency Pack: $327/month for 3 dedicated US-based IPs and unlimited inboxes
Key features:
- Automated DNS configuration (no manual SPF/DKIM/DMARC setup)
- Dedicated US-based IPs on all plans
- Microsoft cloud infrastructure with enterprise partnership
- Domain blacklist monitoring with auto-delisting requests
- CSV export for Instantly.ai or Smartlead integration
Setup speed: Customer testimonials report creating 10 inboxes in 2 minutes. One user described setting up 1,000+ email accounts with all records added within 10 minutes.
"Compared to other ESP providers, using Inframail kinda feels like magic. As soon as you start the process of creating email accounts, it will automatically start adding all the records for you, and show you the process in real-time." - Verified user review of Inframail
Inframail currently has 38 5-star reviews on Trustpilot, reflecting its reliability for high-volume senders.
Pros:
- Flat-rate unlimited model decouples cost from volume
- Dedicated IPs protect reputation from other users
- Automated setup eliminates DNS configuration bottleneck
- Strong support with quick response times
Cons:
- Microsoft-only (no Google Workspace option)
- Requires external warmup tools
- US-based infrastructure only
Verdict: The clear winner for cost-conscious agencies running 50+ domains. The flat-rate model means your infrastructure costs don't scale with client growth, and dedicated IPs mean you're not gambling your reputation on shared pools.
2. Mailforge
Best for: Agencies wanting shared infrastructure at competitive per-inbox rates
Mailforge operates on a shared IP pool model similar to Maildoso. The platform distributes mailbox accounts across a large user base. A Salesforge comparison video outlines the differences between Mailforge and dedicated alternatives like Inframail.
Pricing:
- Per-inbox model starting around $2-3 per mailbox per month
- Pricing scales with account count
- Minimum slot requirements apply
Key features:
- Shared IP infrastructure with large pool distribution
- Integration with major cold email platforms
- 4.8/5 rating on G2 with 74 reviews
Setup speed: Approximately 3 minutes per domain based on platform reports
Pros:
- Strong user rating on G2
- Large shared pool may dilute individual bad actor impact
- Competitive per-inbox rates
Cons:
- Shared IP architecture still creates neighbor risk
- Per-inbox pricing scales costs with volume
- Not dedicated IPs per mailbox
Verdict: A middle-ground option if you're committed to shared infrastructure but want a larger pool than Maildoso. The economics still punish scale, and you lack the reputation isolation of dedicated IPs.
3. Zapmail
Best for: Agencies needing separate workspaces for different clients with pre-warmed account options
Zapmail focuses on workspace organization and offers both Google Workspace and Microsoft accounts with EU and US IP options.
Pricing:
- Starter Plan: $24/month (renew) for 3 accounts ($39 first month)
- Pre-warmed accounts: $39 first month, $24/month thereafter
- Scales based on account count, roughly $2.50/inbox
Key features:
- Separate workspaces for client organization
- Google Workspace accounts with EU and US IP addresses
- Integrates with 50+ cold outreach tools
- Pre-warmed account options available
Setup speed: Standard domain configuration timeframes apply
Pros:
- Geographic IP options (EU and US)
- Client workspace separation built in
- Google Workspace support
Cons:
- Per-account pricing creates linear cost scaling
- Pre-warmed accounts add significant cost
- Shared infrastructure concerns remain
Verdict: Consider Zapmail if you need EU IP addresses or strong workspace organization for multiple clients. The per-account model still punishes scale compared to flat-rate alternatives.
4. Mailreef
Best for: Premium-focused agencies willing to pay more for server-level control and strict compliance requirements
Mailreef takes a different approach by providing dedicated mail servers where you can create unlimited mailboxes on your server at no extra cost.
Pricing:
- Agency Plan: $249/month base price plus $0.001 per email sent fee
- Requires application approval
Key features:
- Dedicated server infrastructure
- Unlimited mailboxes on your server
- Domain health and sender reputation monitoring
- API access and Zapier integration
- Every customer screened and approved
Setup speed: Varies based on approval process
Pros:
- True dedicated infrastructure with server-level control and unlimited mailboxes once approved
- Hyper-focused on IP security
- Pre-vetted user base reduces bad actor risk
Cons:
- Per-email charge adds variable cost on top of base fee
- Limited integrations (only 2 cold email automation tools, no Zapier connectivity for external workflows)
- Application approval creates barrier to entry
- Higher base price point
Verdict: Mailreef is the premium choice for agencies where compliance and IP security are non-negotiable. The screening process means cleaner infrastructure, but the per-email charge and limited integrations add friction. For an average of 40 emails per inbox per month, the variable cost adds up as you scale.
5. Salesforge
Best for: Teams wanting an all-in-one platform combining sending, infrastructure, and AI personalization
Salesforge bundles infrastructure, warmup, and AI-powered sending into a single subscription. This is less a pure infrastructure play and more a complete outreach solution. You can see a detailed comparison with Inframail on their channel.
Pricing:
- Pro Plan: $48/month
- Growth Plan: $80/month for sales teams
- Unlimited mailbox connections included
Key features:
- Unlimited mailbox connections from Google and Outlook
- AI-powered warmup included
- Email generation in 20+ languages
- Full sending platform built in
Setup speed: Integrated workflow handles setup within the platform
Pros:
- All-in-one solution eliminates vendor fragmentation
- AI warmup included at no extra cost
- Strong deliverability reputation among users
- Base plan includes premium warmup and inbox tracking
Cons:
- Limited integration with external marketing tools
Verdict: Choose Salesforge if you want everything in one place and don't need to integrate with separate sending platforms. If you're already using Instantly or Smartlead and just need infrastructure, a pure infrastructure provider makes more sense.
6. Mailscale
Best for: Agencies wanting tiered pricing with a deliverability guarantee
Mailscale offers tiered plans based on mailbox count with automated SPF, DKIM, and DMARC setup.
Pricing:
- Base plan: $79/month for 15 accounts
- Business/Agency: $119/month for up to 50 accounts
- Enterprise: $249/month for up to 200 accounts
Key features:
- Set up 50 to 1,000 inboxes in under a minute
- Automated DNS configuration
- Deliverability guarantee with recovery support
- Up to 5x cheaper than Google/Outlook direct
Setup speed: Claims under 1 minute for bulk inbox setup
Cost for 200 inboxes: $249/month on Enterprise tier (roughly $1.25/inbox)
Pros:
- Fast bulk setup
- Deliverability guarantee provides some protection
- Tiered model offers flexibility at different scales
- Recovery support if issues arise
Cons:
- Shared infrastructure concerns
- Per-inbox model still scales costs (though slower than Maildoso)
Verdict: Mailscale's Enterprise tier at $249/month for 200 accounts beats Maildoso's per-inbox rates at that volume. But compare this to Inframail's $129/month unlimited: Mailscale costs $120/month more for the same inbox count, and you're still on shared infrastructure.
7. Infraforge
Best for: High-volume agencies and lead gen providers needing dedicated IPs with enterprise-grade scaling
Infraforge (distinct from Inframail) provides dedicated IP addresses with automated provisioning and multi-IP distribution for safe scaling.
Pricing:
- Starting at $4 per mailbox per month (minimum 10 slots)
- $33/month (billed yearly) or $40/month (billed quarterly) for the entry tier
- Bulk discounts available for high volume
Key features:
- Dedicated IP addresses for better sender reputation management
- Automated provisioning with free DNS setup
- Multi-IP distribution for scaling
- Domain masking with SSL and proxies
- White-label reseller program for agencies
Setup speed: DNS and infrastructure deployment fully automated for fast onboarding
Estimated cost for 100 inboxes: $400/month ($4.00 per mailbox)
Pros:
- Full deliverability control with dedicated IPs
- Enterprise-grade scaling capabilities
- White-label options for agency resale
- Strong support reputation
Cons:
- Per-mailbox pricing still scales costs
- Best suited for high-volume (overhead doesn't justify small operations)
- Requires deliverability knowledge to optimize
Verdict: Infraforge offers dedicated IPs, which solves the shared pool problem, but the per-mailbox pricing means you pay more as you scale. At 200 inboxes, you're looking at $800/month compared to Inframail's $129/month flat rate.
8. Google Workspace (The traditional baseline)
Best for: Agencies where native Google deliverability is non-negotiable and budget isn't the primary constraint
Google Workspace remains the deliverability gold standard. Google's infrastructure provides native trust signals that some ESP configurations can't match. A Lead Gen Jay video explores what industry insiders know about Google mailboxes.
Pricing:
- Business Starter: $8.40/user/month (monthly) or $7/user/month (annual)
- Enterprise plans require custom quotes
Key features:
- Native Google deliverability
- Industry-leading security
- Full productivity suite (Drive, Docs, Sheets, Meet)
- 24/7 support
Setup speed: Variable. Manual DNS configuration happens at the domain level, with propagation taking anywhere from minutes to hours depending on your registrar.
Cost for 100 inboxes: $700-$840/month
Cost for 200 inboxes: $1,400-$1,680/month
Pros:
- Highest deliverability baseline
- Comprehensive productivity tools included
- Established trust with email service providers
- 24/7 support
Cons:
- Per-inbox pricing is expensive at scale
- Manual DNS setup creates operational bottleneck
- Overkill for cold email-only inboxes
Verdict: Google Workspace makes sense when deliverability to Google recipients is mission-critical and you can absorb the cost. But for pure cold email infrastructure, you're paying premium prices ($1,400+/month at 200 inboxes) for productivity features you don't use.
Comparison table: Maildoso vs top competitors
Provider | Pricing Model | IP Type | Cost for 100 Inboxes | Cost for 200 Inboxes | Warmup Included |
|---|---|---|---|---|---|
Inframail | Flat-rate | Dedicated (1-3) | $129/mo | $129/mo | No |
Maildoso | Per-inbox ($1.40-1.80) | Shared | $140-180/mo | $280-360/mo | No |
Mailscale | Tiered | Shared | $249/mo | $249/mo | No |
Mailforge | Per-inbox | Shared (large pool) | $200-300/mo | $400-600/mo | Partial |
Mailreef | Base + per-email | Dedicated (server) | $253/mo | $257/mo | No |
Salesforge | Subscription | Mixed | $80/mo | $80/mo | Yes |
Infraforge | Per-inbox ($4) | Dedicated | $400/mo | $800/mo | No |
Google Workspace | Per-user ($7-8.40) | Shared | $700-840/mo | $1,400-1,680/mo | N/A |
Key insight: Inframail is the only platform where your cost stays flat as you scale from 100 to 200 to 500 inboxes. Every other provider either charges per-inbox (creating linear cost growth) or has volume limits.
How to choose the right infrastructure for your agency
Calculating your true cost per inbox
The headline price isn't your real cost. You need to calculate total cost of ownership (TCO) including:
1. Platform fee: Monthly subscription or per-inbox charge
2. Domain costs: $16.44/year for .com and $9.44/year for .info
3. Warmup tools: $15-50/month per inbox if not included
4. Sending platform: Instantly, Smartlead, etc.
Here's the formula:
Monthly TCO = Platform Fee + (Domains ÷ 12) + Warmup Costs
At 100 inboxes (50 domains, 2 inboxes per domain), Inframail's platform fee of $129 plus approximately $68.50 in amortized domain costs ($16.44 * 50 / 12) gives you $197.50/month before warmup. Maildoso's $160 platform cost plus $68.50 in domains reaches $228.50/month. Google Workspace at $700 plus domains hits $768.50/month.
The savings compound at scale. Moving from 100 to 200 inboxes on Inframail adds $0 to your platform fee. On Maildoso, it adds $140-180/month.
"So affordable that it will make your unit economics work, even for lower ticket b2b businesses like ours." - Verified user review of Inframail
Assessing deliverability and IP reputation
Shared IPs are a gamble. You might get placed on a clean pool where everyone follows best practices, or you might share an IP with someone sending spam. You have no control over this.
Test your IP reputation using:
1. MXToolbox Blacklist Check: Tests your IP against 100+ DNS-based email blacklists
2. Mail-Tester: Send a test email and get a comprehensive deliverability report with spam score, SPF/DKIM validation, and blacklist status
Check your campaign metrics for spam indicators regularly. For agencies sending 150,000+ emails per month, dedicated IPs become essential. At that volume, a blacklist event affects too many client campaigns to accept the shared pool risk.
Decision tree: Picking your platform
Start here: How many inboxes do you need?
- Under 50 inboxes: Per-inbox pricing (Maildoso, Mailscale base tier) may work. Cost stays manageable, and shared IP risk is lower at small volumes.
- 50-200 inboxes: Flat-rate with dedicated IPs (Inframail) provides the best economics. Per-inbox costs start compounding, and shared IP exposure increases.
- 200+ inboxes: Flat-rate is non-negotiable. At this scale, per-inbox pricing costs $150-600/month more than flat-rate alternatives.
Next question: Google or Microsoft?
- Google required: You're limited to Google Workspace, Zapmail, or Salesforge (which supports Google accounts)
- Microsoft acceptable: Inframail offers the best flat-rate economics on Microsoft infrastructure
Final filter: All-in-one or infrastructure only?
- Already using Instantly/Smartlead: Choose a pure infrastructure provider (Inframail, Mailscale, Mailreef)
- Want everything bundled: Salesforge combines infrastructure, warmup, and sending
Watch the Ultimate Cold Email Infrastructure Guide for a comprehensive walkthrough of setup best practices.
The bottom line on Maildoso alternatives
Maildoso works for agencies starting out. The per-inbox pricing is accessible, and setup is straightforward. But the architecture creates two ceilings: your costs scale linearly with volume, and your reputation depends on strangers' behavior.
For agencies scaling beyond 50 domains, flat-rate pricing and dedicated IPs are no longer nice-to-haves. They're the difference between infrastructure that supports growth and infrastructure that punishes it.
Inframail provides both: $129/month for unlimited inboxes on dedicated US-based IPs, built on Microsoft's cloud infrastructure. Whether you're running 50 inboxes or 500, your infrastructure cost stays the same, and your reputation stays isolated.
"I've been using inframail and what i liked most about them is the support. They are very quick to respond and solve all requests within a short time. I liked the price compared to other platforms." - Verified user review of Inframail
If you're running 50+ domains and ready to decouple infrastructure costs from client growth, Sign up to Inframail and get started today.
Frequently asked questions
Is Inframail better than Maildoso for agencies?
Yes, for agencies running 50+ domains. Inframail costs $129/month flat regardless of inbox count, while Maildoso charges $1.40-1.80 per inbox. At 100 inboxes, that's $129 vs $140-180/month, and Inframail includes dedicated IPs while Maildoso uses shared pools.
Does Maildoso use shared or dedicated IPs?
Shared. Maildoso's pricing is based on shared IP infrastructure, meaning your sending reputation depends on other users on the same pool.
What's the fastest cold email infrastructure to set up?
Mailscale claims under 1 minute for bulk inbox setup. Inframail users report 10 inboxes in 2 minutes with automated DNS configuration.
How much does Google Workspace cost for 100 cold email inboxes?
$700-840/month at $7-8.40 per user. This makes it the most expensive option for pure cold email infrastructure.
Do I need a separate warmup tool with Inframail?
Yes. Inframail is infrastructure-only. You'll need an external warmup tool. Learn more about warming up your inboxes in the help documentation.
Can I use my existing domains with Inframail?
Yes. You can add existing domains and Inframail will configure all DNS records automatically.
Key terms glossary
Dedicated IP: An IP address assigned exclusively to your sending. Your reputation depends only on your own behavior, not other users.
Shared IP pool: Multiple users send from the same IP addresses. One user's spam complaints can damage deliverability for everyone on that pool.
SPF/DKIM/DMARC: Email authentication protocols. SPF validates sender servers, DKIM adds cryptographic signatures, DMARC tells receivers how to handle authentication failures.
Flat-rate pricing: A fixed monthly fee regardless of usage volume. Eliminates per-seat cost scaling as you add inboxes.
Per-inbox pricing: Charges scale with the number of mailboxes. Creates linear cost growth as you add clients.
TCO (Total Cost of Ownership): The complete cost including platform fees, domain costs, warmup tools, and sending platform subscriptions.
Inbox placement rate: The percentage of sent emails that land in recipients' primary inbox rather than spam or promotions folders.
