
Sendmux.ai
Nylas Mail
Evolution
Mails.ai
Mailbird
LobsterMail.ai
Sequenzy
Email for AI agents. Create mailboxes, send and receive email via REST API. No SMTP, no OAuth. 30-day money-back guarantee.

Nylas Mail
Evolution
Mailbird
Mailpile
Polymail
Email infrastructure for AI agents. Inbound is parsed, classified, extracted to your schema — and screened for prompt injection — before your agent reads a word.

Which is more popular?
Website, pricing, platforms and company facts side by side.
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|---|---|---|
| Website | robotomail.com | postfleet.ai |
| Pricing | ||
| Platforms | — | |
| Company | 1 - 9 employees · 2026 | Startup from the United States · 1 - 9 employees · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.


Robotomail provides email infrastructure for AI agents, giving each agent a real mailbox it can create, send from, receive to, and manage via API. Provision mailboxes with one POST, send and receive messages, and handle threading automatically. Get real-time inbound through webhooks or SSE,...
Postfleet is inbound email infrastructure for AI agents, built on the assumption that any message can be an attack. Every message runs the same pipeline before your agent sees it: SPF/DKIM/DMARC checks, HTML-to-text cleaning, removal of hidden elements, HTML comments and zero-width characters,...
What each product offers, as listed by its team.


An editorial look at what each product does well and who it suits.


Overall verdict
Why this product is good
Recommended for
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How to Give Your AI Agents an Email Address
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How often each product is chosen within a category, 0–100% relative to the other.


As answered by people managing Robotomail and Postfleet.
Postfleet's answer:
It treats an agent's inbox as a trust boundary, not a pipe. Every inbound email is screened for prompt injection, stripped of hidden text, and turned into structured JSON before the agent ever reads it. The unusual part: I red-team the filter with rival models and publish the whole scoreboard, catches and misses both. Screened, never immune.
Postfleet's answer:
Most email APIs for agents hand you the raw body and leave defense to your app layer. Postfleet screens first and fails closed, so flagged mail reaches the agent as inert data instead of trusted content. It's backed by an injection guarantee and a public red-team scoreboard, so the security claim comes with receipts rather than a marketing number.
Postfleet's answer:
Developers building AI agents that receive email: indie hackers, agent-framework builders, and small platform teams wiring an agent to an inbox. People who've read at least one prompt-injection horror story and would rather see published results than take a claim on faith.
Postfleet's answer:
I've spent 18 years building software, the last 6 as an architect drawing trust boundaries between systems that shouldn't blindly trust each other. When I watched people give AI agents email inboxes, I saw the boundary everyone skipped: anyone who can email an agent can drop instructions into its context. Postfleet is that missing boundary.
Postfleet's answer:
Next.js, TypeScript, and Supabase (Postgres), deployed on Vercel. An MCP server so an agent can sign itself up. Anthropic models run the injection scan and schema extraction, Resend/SES handles inbound mail, and ClamAV scans attachments.
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