Maildoso

Maildoso sells cold-email mailboxes on its own sending infrastructure rather than on Google or Microsoft accounts, at prices that set the floor of the market: $2.50 a mailbox at 30 mailboxes, $0.75 at 300, $0.49 at 1,000. Every plan includes "self-healing mailboxes", IP rotation, CAPTCHA domain protection, reputation metrics, API and MCP access and a 30-day refund guarantee.

The surprising fact is how it sells: on cost per email, not cost per inbox. Maildoso's pricing page claims $33 per 1,000 emails versus $165 on Google Workspace and $250 on Azure tenants. The arithmetic only works as monthly cost per 1,000 emails a day of capacity (1,000 ÷ 15 per mailbox × $0.49 ≈ $33), but it is the right frame, and almost no one else uses it.

#What it sells

• Private-SMTP mailboxes capped at "up to 15 emails per day", with IP rotation.
• "Self-healing" mailboxes (automatic replacement), CAPTCHA protection for domains, per-mailbox reputation metrics.
• API and MCP server access — one of the few infra vendors pitching to AI-agent workflows.
• Free deliverability audits.

The site does not say in so many words that the mailboxes are on its own servers, but it prices itself against Google Workspace and Azure tenants, which implies private SMTP (Maildoso).

#How it prices

Legacy quarterly bundles included domains: 32 mailboxes + 8 domains for $299/quarter up to 400 + 100 for $2,199/quarter. At $0.49 and 15 sends a day over 22 working days, a mailbox costs about $1.50 per 1,000 emails sent before domains — four to eight times cheaper than a reseller Google mailbox (Inbox & domain infrastructure).

#Who uses it and why

Maildoso claims "10M+ emails sent daily", "400k+ mailboxes", "7,000+ companies" and a 4.7 rating from 197 G2 reviews. The steep discount curve targets high-volume Lead-gen agencies that need thousands of sending slots and treat each as disposable.

#Where it is strong

• Price. No other vendor reviewed lists a mailbox under $1.
• Cost-per-send framing. It sells the metric agencies actually budget on.
• No Google or Microsoft account to suspend. Immune to the autumn 2025 Google wave (Provider crackdowns) by construction.
• Agent-ready. API plus MCP access is ahead of most of the infra layer.

#Where it is weak

• Shared reputation. Private-SMTP pools inherit their neighbours' behaviour, and recipients see mail from a small sender's IPs rather than Google's or Microsoft's — the ESP matching benefit is lost. See Google vs Microsoft vs SMTP.
• Low per-mailbox cap. 15 a day means more domains and more mailboxes to manage for the same volume.
• Opacity. The site's legal entity is "BacklinkSwappers, inc." at a San Francisco business-centre address; no founders, funding or team are named.

#Trajectory

Maildoso has moved from quarterly bundles to monthly per-mailbox billing with sharper volume tiers (the page says the new prices apply "as of June 2026"), and added MCP access. Its strategic threat is the sequencers' own SMTP: Instantly's AirMail at $4 per account and Smartlead's resold Mailreef/AeroSend at $3.99–4.20 are far more expensive, but convenient. If the sequencers cut those prices, standalone SMTP vendors lose their wedge.

#What this means for an entrant

• Cost per 1,000 sends is the honest metric — use it. Show customers what each inbox type costs per email in your app; nobody else does.
• A sub-$1 SMTP mailbox is the price anchor. If you resell SMTP, your customers will compare it with Maildoso's $0.49.
• SMTP vendors are natural wholesale partners. Like Smartlead with Mailreef, a new sequencer can resell Maildoso-class capacity without running MTAs. See Infrastructure strategy: build or partner.
• MCP access is a signal. Infra that AI agents can provision through tools is where the The AI shift meets this layer; build your API accordingly.