Mailly vs AgentMail
Mailly and AgentMail compared for AI agent email, including pricing, free-tier limits, agent sign-up, MCP, IMAP/SMTP and human review. Checked October 15, 2026.
As of October 15, 2026
This comparison is published by Mailly. Prices and features come from each provider's public pages on October 15, 2026, and may have changed since. Check AgentMail pricing and Mailly pricing for current numbers.
In short
- Both give AI agents real two-way inboxes with an API, an MCP server, webhooks, and custom domains on paid plans. Both free tiers include 3 inboxes and 3,000 emails a month.
- AgentMail is email infrastructure for agents at scale: IMAP and SMTP access, websockets, AgentID for signing agents up to third-party apps, Agent Drive, and a Startup plan with 150 inboxes and SOC 2.
- Mailly centers on agent email that people approve, with marketing tools in the same account: reply drafts you review before they're sent, hosted agents that summarize incoming mail, and templates, contacts, audiences, campaigns and workflows.
Pricing
| Mailly | AgentMail | |
|---|---|---|
| Free | $0: 3 inboxes on @mailly.site, 3,000 emails/month, 100 send recipients per rolling 24 hours, US$1 monthly usage allowance, no custom domains | $0: 3 inboxes, 3,000 emails/month, 100 emails/day, 3 GB storage, "Sent via AgentMail" footer, no custom domains |
| Around $20/month | Developer, $20/month or $200/year: 10 inboxes, 10 custom domains, 30,000 emails/month, US$10 monthly usage allowance, no plan daily cap | Developer, $20/month: 10 inboxes, 10,000 emails/month, 1,000 emails/day, 10 custom domains |
| Larger plans | Enterprise: limits and price by contract | Startup, $200/month: 150 inboxes, 150 domains, 15,000 emails/day, SOC 2. Enterprise: custom |
| Beyond the plan | $1 per 1,000 emails over the included count, paid as used from a prepaid balance (top-ups from US$5 to US$1,000, no automatic top-ups) | Monthly add-ons: $2 per inbox, $2 per domain, $2 per 1,000 extra emails, $5 per seat |
Both offer yearly billing. The two count email differently: Mailly's monthly count includes received messages, and each To, Cc and Bcc recipient of a sent email counts once; quarantined spam isn't charged. With no plan daily cap, Mailly's account sending-safety limits still apply. Mailly's free plan can be topped up without subscribing, but top-ups don't raise inbox, domain or sending-safety limits.
Features
| Mailly | AgentMail | |
|---|---|---|
| Agent sign-up | The agent reserves the name you choose over a public HTTP endpoint; you verify with your own email and confirm, then the agent receives the address and your API key. | Sign-up API for agents, with a one-time code sent to a person's email |
| MCP | Remote MCP with OAuth and four permission scopes (read, draft, send, manage); about 70 tools | MCP server with about 45 tools |
| Protocols | HTTP API, SMTP for sending, CLI (mailly-cli). No IMAP. | API, IMAP and SMTP |
| Real-time events | Signed webhooks for incoming mail and delivery events | Webhooks and websockets |
| Human review | Reply drafts wait for approval of the exact text; hosted agents can only draft. No shareable review link. | Drafts, without a human review link |
| Web console | Full workspace: inbox, sent mail, domains, agents, campaigns and workflows | Web console with Gmail-like webmail |
| Beyond the inbox | Templates, contacts, audiences, campaigns, event-driven workflows, hosted agents with automatic summaries of incoming mail | AgentID (agents create accounts at 40+ third-party apps), Agent Drive |
Where AgentMail is stronger
- IMAP access and websockets. If your agent or tooling expects IMAP, or you want a websocket stream instead of webhooks, AgentMail supports both. Mailly offers SMTP for sending only.
- Scale and compliance. AgentMail's Startup plan lists 150 inboxes, 150 domains and SOC 2 for $200 a month, and you can add inboxes and domains for $2 each.
- Agents acting on other services. AgentID lets agents create accounts at more than 40 third-party apps, and Agent Drive adds file storage. Mailly has no equivalent.
- Track record. AgentMail is a Y Combinator company with a $6M seed round.
Where Mailly is stronger
- More email per dollar. The $20 Developer plan includes 30,000 emails a month instead of 10,000, with no plan daily cap, and extra email costs $1 per 1,000 as you use it instead of a $2 monthly add-on.
- No branding footer on Free. AgentMail's free plan adds "Sent via AgentMail"; Mailly adds no branding to your mail. The only footer Mailly adds is the unsubscribe link on marketing and lifecycle email, with your own brand name and postal address on marketing mail.
- Human approval is built in. Hosted agents can only draft, and MCP sending tools require you to review the exact text and recipients before anything is sent.
- Email marketing and automation in one place. Templates, contacts, audiences, campaigns and event-driven workflows share the same inboxes and API.
- Hosted agents. A Mailly agent can summarize each incoming email with your own prompt and draft replies for review, billed at the model's official token rates with no markup.
Which should you choose?
- Choose AgentMail if you need IMAP or websockets, hundreds of inboxes, SOC 2, or agents that sign up for other services.
- Choose Mailly if people should approve what agents send, you want campaigns and workflows next to agent mail, or you want a hosted agent that summarizes and drafts.
Try Mailly: follow the quickstart or connect your AI client. See also Mailly vs Botmail and Best email for AI agents.
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