Comparison
Jan 30, 2026
CEO and co-founder
Zapmail vs Maildoso: Which Fits Your Agency Stack?
Zapmail vs Maildoso: The high-level verdict for agencies
Both Zapmail and Maildoso position themselves as Google Workspace alternatives for cold email operations. They automate DNS configuration (SPF, DKIM, DMARC), provide SMTP/IMAP credentials, and integrate with sending platforms like Instantly and Smartlead.
The core difference comes down to pricing structure and IP infrastructure:
Zapmail charges $2.50-$4 per mailbox depending on your plan tier, with renewal pricing increases after year one according to Outreach Almanac's Zapmail analysis
Maildoso charges $1.90-$3.10 per mailbox with mandatory quarterly billing on some plans, as noted in the Salesforge comparison of Maildoso alternatives
Both rely primarily on shared IP pools, meaning other users' sending behavior affects your deliverability
For agencies managing 50+ domains across multiple clients, these per-inbox costs compound quickly. A 100-inbox operation on Zapmail using the Pro plan costs around $299/month in mailbox fees alone. That's before you add domains, warmup tools, and your sending platform.
We built Inframail as a flat-rate alternative specifically for this scale problem. Our $129/month Unlimited plan covers unlimited inboxes on dedicated US-based IPs, and our platform handles DNS configuration automatically. The Ultimate Cold Email Infrastructure Guide for 2025 walks through the full setup workflow if you want to see it in action.
Key terminology for this comparison:
Term | Definition |
|---|---|
Cold email infrastructure | The backend systems (domains, mailboxes, IPs, DNS records) that enable outbound email campaigns |
Deliverability | The percentage of emails that reach the recipient's inbox vs spam folder |
SPF/DKIM/DMARC | DNS authentication records that verify sender legitimacy and improve inbox placement |
TCO | Total Cost of Ownership, including all fees (platform, domains, warmup, sending tools) |
Warmup | The process of gradually increasing email volume on new inboxes to build sender reputation |
Feature breakdown: Automation, warmup, and sending limits
DNS automation
Zapmail provides automated DNS setup for SPF, DKIM, and DMARC records. Their platform handles DNS configuration automatically, reducing the manual work that traditionally required accessing Namecheap, GoDaddy, or Cloudflare panels directly. Woodpecker's infrastructure review notes that Zapmail "handles provisioning, authentication (SPF, DKIM, DMARC), warm-up automation, and deliverability monitoring in-house."
Maildoso also offers automated DNS configuration. Their setup process registers mailboxes within 15 minutes with SPF, DKIM, and DMARC auto-configured according to Infraforge's comparison of email infrastructure tools. Both platforms handle the technical DNS work.
The catch with both platforms: you're still paying per mailbox for this automation. Our Cold Email Setup: SPF, DKIM, and DMARC video demonstrates a 2-minute setup for 10+ inboxes on flat-rate infrastructure.
Warmup capabilities
Zapmail offers pre-warmed mailboxes and warmup features integrated into their platform. Their Zap Shield add-on provides ongoing warmup and deliverability support.
Maildoso does NOT include built-in warmup in the base price. Their AI warmup feature costs an additional $160-$2,000/month and only works with Gmail and Outlook mailboxes, as confirmed by the Salesforge Maildoso alternatives analysis. If you're using their native SMTP accounts, you'll need external warmup tools like Warmbox ($15-50/month per inbox) or Lemwarm.
Inframail also requires external warmup tools for the Unlimited and Agency Pack plans. However, our Done-for-You Email Campaign Setup package includes free email account warmup. The how to warm up your inboxes guide covers the process for self-service users.
Sending platform integrations
Both Zapmail and Maildoso export credentials to major cold email tools:
Instantly
Smartlead
Reply
Lemlist
ReachInbox
The integration process involves exporting SMTP/IMAP credentials via CSV and importing to your sending platform. Our help documentation on compatible platforms confirms the same workflow for Inframail.
Pricing models exposed: The hidden cost of per-inbox scaling
This is where the comparison gets real. Let me break down the actual math.
Zapmail pricing structure
Based on Outreach Almanac's Zapmail pricing breakdown, Zapmail's pricing tiers include:
Starter: $39/month for 10 mailboxes ($3.90/mailbox)
Growth: $129/month for 30 mailboxes ($3.30/mailbox)
Pro: $299/month for 100 mailboxes ($2.99/mailbox)
Standard with Admin Access: $4/mailbox + $15/domain/year
After year one, renewal pricing kicks in:
Starter Plan: $59/month + $6/mailbox add-on
Growth Plan: $169/month + $5.50/mailbox add-on
No free trial or free plan is available, requiring commitment before testing deliverability with real campaigns.
Maildoso pricing structure
According to Infraforge's email infrastructure comparison, Maildoso's tiered approach includes:
Base: $100/month for 32 mailboxes ($3.13/mailbox)
Mid-tier: Scales down to approximately $2.75/mailbox at higher volumes
High-volume: Approximately $1.80/mailbox for 400+ mailboxes ($733/month)
The quarterly billing quirk: Maildoso requires quarterly commitment on some plans with no discount for the longer commitment. The Small Package starts at $99 every three months (12 email accounts, 3 domains).
The scale trap in action
Let me run the numbers for a 100-domain agency running 200 inboxes (2 inboxes per domain for rotation):
Cost Component | Zapmail | Maildoso | Inframail |
|---|---|---|---|
Platform fee (200 inboxes) | ~$599/mo (Pro + 100 add-ons at $3/each) | ~$550/mo | $129/mo |
Domain costs (100 domains) | ~$125/mo amortized | Included in some plans | ~$137/mo amortized |
External warmup (if needed) | Varies | $160-2,000/mo | $15-50/inbox or DFY included |
Monthly total (no warmup) | ~$724 | ~$550 | ~$266 |
Zapmail and Maildoso pricing based on their published rates as of January 2026. Domain costs calculated using industry-standard $13/year average.
The savings compound as you scale. At 200 inboxes, Inframail saves approximately $300-$500/month compared to these per-inbox alternatives. That represents thousands in annual savings that stays in your margin instead of funding infrastructure.
As one Inframail user described:
"So affordable that it will make your unit economics work, even for lower ticket b2b businesses like ours" - Verified user review of Inframail (Inframail now has [38 5-star reviews on Trustpilot](https://www.trustpilot.com/review/inframail.io).)
The video on dedicated IP vs shared IP pools explains why infrastructure costs matter beyond just the monthly bill.
Deliverability and infrastructure: Shared pools vs dedicated IPs
Infrastructure type directly impacts your inbox placement rates. Here's the fundamental difference:
Shared IP pools work like carpool lanes where you're affected by other drivers. One bad actor spamming gets the whole IP range flagged. Your deliverability drops because someone you've never met sent 50,000 emails to purchased lists.
Dedicated IPs work like private lanes where your behavior alone determines reputation. You control the sending volume, warm up the IP on your timeline, and don't inherit reputation damage from other users.
Zapmail IP infrastructure
According to multiple third-party reviews including Woodpecker's analysis, Zapmail operates primarily on shared US/EU IPs. While they offer some deliverability monitoring features, they don't offer dedicated IPs in standard plans, which limits control for teams with strict deliverability requirements.
Maildoso IP infrastructure
Maildoso explicitly uses shared IP addresses with heavy IP rotation, as confirmed by Infraforge's infrastructure comparison. You share the same sending infrastructure with other users. If another user on your IP misbehaves, your deliverability suffers.
The Salesforge Maildoso alternatives review notes that Maildoso's shared IP approach keeps costs low but comes with risks when other users on the same IP send problematic campaigns.
Inframail IP infrastructure
We provide dedicated US-based IPs on every plan:
Unlimited Plan ($129/mo): 1 dedicated IP
Agency Pack ($327/mo): 3 dedicated IPs
Built on Microsoft's cloud platform with our publicly announced enterprise partnership (January 2024), your sending reputation stays isolated from other users. The Mailreef vs Mailscale vs Inframail comparison video breaks down the dedicated server vs shared pool differences in detail.
"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
User sentiment: What verified reviews say about support and uptime
Zapmail user feedback
Based on verified user reviews from G2 and Trustpilot profiles:
Positive themes from reviews:
Quick and detailed support responses, including outside business hours
Easy-to-use interface
Automation features (DKIM, SPF, DMARC setup) reduce setup time significantly
Competitive pricing compared to Google Workspace
Negative themes from reviews:
Microsoft 365 inbox disconnects reported by some users
Limited advanced deliverability safeguards at higher volumes
Some users found the value proposition unclear for their specific use case
Zapmail pros:
Automated DNS configuration
Pre-warmed mailbox options
Direct integrations with Instantly, Smartlead
Responsive support team
Zapmail cons:
Per-mailbox pricing scales with growth
Shared IP infrastructure
Renewal pricing increases after year one
Maildoso user feedback
Based on feedback documented in Salesforge's analysis and Infraforge's comparison:
Positive themes:
Setup is among the easiest in the market (10-15 minutes for multiple domains and mailboxes)
Deliverability scores visible for each inbox
Low cost entry point
Negative themes:
Shared IP issues affecting deliverability for some users
Interface navigation can be confusing at first
Mandatory quarterly billing with no discount
Portal issues requiring support contact
Inframail user feedback
Our Trustpilot profile shows strong user sentiment across verified reviews. Common themes:
"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
"We spent months hunting for a reliable cold-emailing stack. After repeated failures with another provider, we trialled two options—Inframail and a competitor. We chose the competitor. A month later, we switched back to Inframail. Zero issues since." - Verified user review of Inframail
The 6 Calls PER DAY user interview features Jackson Williams discussing his approach to booking sales calls using Inframail infrastructure.
The third option: Why agencies are switching to flat-rate infrastructure
The pattern I see repeatedly: agencies start with per-inbox providers because the entry cost looks lower. Then they hit 50-75 inboxes and realize their infrastructure bill is growing faster than their revenue.
Complete feature comparison
Feature | Zapmail | Maildoso | Inframail |
|---|---|---|---|
Pricing model | Per-mailbox ($2.50-$4) | Per-mailbox ($1.90-$3.10) | Flat-rate ($129/mo unlimited) |
IP type | Shared (US/EU) | Shared with rotation | Dedicated (1-3 IPs) |
DNS automation | Yes | Yes | Yes (1-click) |
Built-in warmup | Pre-warmed available | Add-on ($160-2K/mo) | External required (or DFY included) |
Billing flexibility | Monthly | Quarterly required | Monthly or annual |
Support response | Good | Mixed reviews | 16 hours daily (7am-12am PST) |
Why the math favors flat-rate at scale
For SDR managers running 80+ inboxes: your infrastructure cost stays fixed as you add team members and client campaigns. No seat counting, no overage calculations.
For campaign managers launching new clients: setup drops from hours to minutes. The InfraMail Setup Tutorial by Shivam Gupta shows the step-by-step workflow.
"I personally have over 1,000 email accounts with Inframail for one flat price. Adding all those records would have probably taken dozens of hours. Instead all records were added within 10 minutes." - Verified user review of Inframail
The How to Create Unlimited Cold Email Inboxes demo shows the actual provisioning process.
"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
Final recommendation: When to choose which platform
Choose Zapmail if:
You have fewer than 20 domains and need a quick start
You want pre-warmed mailboxes included
You're comfortable with shared IPs and year-one promotional pricing
Monthly billing flexibility matters more than long-term cost
Choose Maildoso if:
You're testing cold email on a minimal budget (under 30 mailboxes)
Quarterly billing doesn't disrupt your cash flow
You have technical capacity to troubleshoot portal issues
You're okay with shared IPs
Choose Inframail if:
You manage 50+ domains and need predictable infrastructure costs
Protecting 15-20% net margins is a priority
You want dedicated IPs to control your sender reputation
You need responsive support with real humans
"Inframail and the team have been such an amazing experience from day one. At first I was skeptical on how legit the service was, considering the price point, but as soon as I started creating email accounts I was blown away." - Verified user review of Inframail
The $1M Agency interview with Dillon Andrew covers how successful agencies approach infrastructure decisions at scale.
Sign up to Inframail and get started today. Our FAQ documentation answers common setup questions, and the email sending capacity calculator helps you determine the right plan for your volume.
Frequently asked questions
What are the main features of Zapmail?
Zapmail provides automated DNS setup (SPF, DKIM, DMARC), Google Workspace mailboxes at $2.50-$4/month per inbox, pre-warmed mailbox options, and integrations with Instantly, Smartlead, and other sending platforms.
How does Zapmail pricing compare to alternatives?
Zapmail's $2.50-$4/mailbox costs less than Google Workspace ($7-8.40/inbox) but more than flat-rate providers at scale. For 200 inboxes, Zapmail costs approximately $724/month vs Inframail's approximately $266/month total.
What do users say about Zapmail in reviews?
Users praise responsive support and easy setup, but some note Microsoft 365 instability and renewal pricing increases after year one.
What are the best Zapmail alternatives?
Maildoso offers lower per-inbox rates ($1.90-$3.10) with quarterly billing. Inframail provides flat-rate unlimited inboxes ($129/month) with dedicated IPs for agencies at scale.
How does Zapmail handle email deliverability?
Zapmail uses shared US/EU IPs with automated DNS authentication and offers some deliverability monitoring features, though dedicated IPs are not available in standard plans.
Does Maildoso include warmup?
No. Maildoso's AI warmup is an add-on costing $160-$2,000/month and only works with Gmail and Outlook mailboxes.
Key terminology
Dedicated IP: An IP address used exclusively by your organization, isolating your sender reputation from other users' behavior.
Shared IP: An IP address used by multiple organizations, where each sender's behavior affects the collective reputation.
DNS propagation: The time required (typically 24-48 hours) for DNS record changes to spread across global servers.
SMTP credentials: Server login details (host, port, username, password) required to send email through a mail server.
