Robotomail (robotomail.com) is a solid, straightforward agent mailbox product, and it has moved since we first wrote this page in August 2026: there is now a permanent free plan, a $79 Growth tier between the old $19 and $199 ones, an MCP server, a CLI, and webhooks with SSE streaming on every plan. Credit where it is due — the 2026 version is a more complete product than the one we originally compared against, and the storage allowances (10–100 GB) are more generous than ours.
Bottom line: the difference is the shape of the meter. Robotomail bills three things separately — mailbox count, monthly sends, and monthly inbound — and adds a per-mailbox daily send cap on top. Dead Simple Email bills one pooled email allowance in both directions, with no daily cap. That matters most for two-way agents: on Robotomail's $19 Developer plan, 15,000 sends come with only 2,000 inbound, so an agent that gets replies runs out of the smaller number first. And on price, $29/mo covers 100 inboxes here against Robotomail's $79 for 50 and $199 for 200.
Pricing Comparison
Robotomail figures as read from its pricing page on 2026-09-16.
| Tier | Dead Simple Email | Robotomail |
|---|---|---|
| Free | 5 inboxes · 5,000 emails/mo · no card | 1 mailbox · 10 sends + 10 receives · no card |
| Entry paid | $5/mo — 15 inboxes, 15,000 emails, 1 domain | $19/mo — 10 mailboxes, 15,000 sends, 2,000 inbound, 1 domain ($9.50 for 3 months) |
| Mid | $29/mo — 100 inboxes, 100,000 emails, 5 domains | $79/mo — 50 mailboxes, unlimited sends, 20,000 inbound, 5 domains |
| Top published | $99/mo — 500 inboxes, 500,000 emails, 25 domains | $199/mo — 200 mailboxes, unlimited sends and inbound, dedicated IPs |
| Cost per mailbox at the top tier | $0.20 | $1.00 |
| Cost for 50 mailboxes | $29 | $79 |
| Cost for 100 mailboxes | $29 | $199 |
| Daily send cap | None | 500, 1,000 or 2,000 per mailbox per day by plan |
| Storage | 1–10 GB pooled by plan | 10–100 GB by plan |
The $29-against-$199 line for 100 mailboxes is the one most fleets land on. Robotomail's $79 Growth plan stops at 50, so the moment you pass it the next step is $199.
Two Meters, Not One
“Unlimited monthly sending” on Robotomail's Growth and Scale plans is real, but it sits next to two other limits. Inbound is metered separately — 2,000 messages a month on the $19 plan, 20,000 on the $79 plan — and each mailbox has a daily send ceiling of 500, 1,000 or 2,000 depending on tier. Inbound over the cap is discarded on the free plan and held until you upgrade or the month resets on paid plans.
For an agent that mostly broadcasts, that shape is fine and the unlimited sending is a genuine advantage. For an agent that holds conversations — support, recruiting, scheduling, procurement — sends and receives run roughly one to one, and the inbound number becomes the real plan size. Dead Simple Email's allowance is one pool: the $29 plan's 100,000 emails can be any mix of sent and received, with no per-day ceiling.
Feature Comparison
| Feature | Dead Simple Email | Robotomail (September 2026) |
|---|---|---|
| Free tier you can build on | 5 inboxes, 5,000 emails/mo, forever | 1 mailbox, 10 sends + 10 receives |
| Inbound metered separately | No — one pooled allowance | Yes — 2,000 to unlimited by plan |
| Daily send cap per mailbox | None | 500 / 1,000 / 2,000 by plan |
| MCP server | Yes — official registry, OAuth 2.1 | Yes |
| CLI | Yes | Yes |
| Webhooks | All plans, with delivery log and replay | All plans |
| SSE streaming | Yes | Yes |
| WebSocket streaming | Yes | Not advertised |
| IMAP / SMTP | Yes — every inbox | Mailbox access |
| Bulk inbox create / delete | Yes | Not advertised |
| Prompt-injection scanning | Yes — scored on every inbound | Not advertised |
| Verification-code / OTP extraction | Yes — dedicated endpoint | Not advertised |
| Visual dashboard | Yes — all plans | Yes |
| Storage | 1–10 GB pooled | 10–100 GB |
| Dedicated IPs | Enterprise | $199 Scale plan |
| SDKs | Python, TypeScript, Go, CLI | API, CLI |
| Agent identity / OIDC sign-in | Yes — Sign in with Dead Simple, free on every plan | No |
| Inbound prompt-injection scanning | Yes: live on every plan, injection_risk and injection_score on every inbound message | No |
| Pay per request without an API key | Yes — x402 USDC and Stripe MPP, $1.00 per inbox | No |
| Calendar per inbox (events, invites, RSVP, ICS feed) | Yes: events, invitations, RSVP, inbound ingestion, ICS feed | No |
| Metrics time-series API | Yes: GET /v1/metrics, day or hour buckets | No |
| Inbox-scoped API keys and webhooks | Yes: inbox_ids on API keys and webhooks | No |
Where Robotomail Wins
- Unlimited sending on Growth and Scale. If your agents send far more than they receive and you can live inside the daily per-mailbox cap, uncapped monthly volume is a real advantage over any pooled allowance.
- Storage. 10 GB on the $19 plan and 100 GB on the $199 one is more room than Dead Simple Email gives, and it matters if your agents keep large attachments.
- Dedicated IPs at $199. Dead Simple Email keeps those for enterprise. If you want IP isolation at 200 mailboxes, Robotomail sells it off the shelf.
- Bundle simplicity. Three plans, three numbers. Nothing to forecast.
Who Should Use Dead Simple Email
- Two-way agents, which hit Robotomail's separate inbound meter before anything else.
- Fleets of 11 to 500 inboxes, where the price gap runs from 4x to 2x.
- Anyone evaluating seriously. One mailbox and ten sends is a demo; five inboxes and 5,000 emails is a pilot.
- Agents that read untrusted mail and need injection scanning and automatic verification-code extraction.
- Agents that provision themselves, through x402 or Stripe MPP with no account at all.
How to Switch from Robotomail
- Sign up for Dead Simple Email — free, no credit card, 5 inboxes immediately.
- Bulk-create inboxes matching your Robotomail mailbox fleet in one API call.
- Repoint your integration — REST API, webhooks, SSE, WebSocket, IMAP, or the MCP server.
- Verify your sending domain — Dead Simple Email guides the MX, SPF, DKIM and DMARC records.
- Cancel the Robotomail plan once traffic is flowing.
Frequently Asked Questions
Dead Simple Email. It gives you more inboxes per dollar at every tier — 15 inboxes for $5 against Robotomail's 10 for $19, 100 for $29 against 50 for $79, and 500 for $99 against 200 for $199 — and pools sends and receives into one allowance rather than metering inbound separately and capping sends per mailbox per day.
As read on 16 September 2026: free for 1 mailbox with 10 sends and 10 receives, $19/mo for 10 mailboxes with 15,000 sends and 2,000 inbound (introductory $9.50 for three months), $79/mo for 50 mailboxes with unlimited sending and 20,000 inbound, and $199/mo for 200 mailboxes with unlimited sending, unlimited inbound and dedicated IPs.
Yes. As of September 2026 Robotomail includes an MCP server, a CLI and API access on all plans, which is a change from earlier in the year. Dead Simple Email's MCP server is listed in the official MCP registry and supports OAuth 2.1, so agents in Claude, Cursor and other MCP clients can authenticate without a pasted key.
Yes, separately from sending. As of September 2026 the free plan discards inbound over its cap, the $19 Developer plan allows 2,000 inbound messages a month, the $79 Growth plan allows 20,000, and the $199 Scale plan is unlimited. On paid plans, inbound over the cap is held until you upgrade or the month resets. Dead Simple Email counts sends and receives against one pooled allowance.
Yes, per mailbox: 500 a day on the $19 plan, 1,000 on the $79 plan and 2,000 on the $199 plan. Dead Simple Email has no daily cap — the monthly allowance is the only limit, so an agent can send its whole month in a day if the work demands it.
Dead Simple Email, at $29/mo for 100 inboxes and 100,000 emails. Robotomail's $79 Growth plan stops at 50 mailboxes, so 100 requires the $199 Scale plan — roughly seven times the price for the same inbox count.
Yes. The free tier is 5 inboxes and 5,000 emails a month, with webhooks, IMAP, the dashboard, the MCP server, injection scanning and verification-code extraction, no card and no expiry. Robotomail's free plan is 1 mailbox with 10 sends and 10 receives.
All Robotomail figures on this page were read from its public pricing page on 2026-09-16 and are reproduced for comparison. Vendors change prices; check the source before making a decision, and tell us if anything here is out of date. Full cross-vendor tables: AI agent email API pricing comparison.