AgentMail is a hosted email provider that creates new inboxes for agents on agentmail.to or your own domain. Fluxmail runs on your machine or server and connects agents to Gmail, Outlook, Exchange, and IMAP mailboxes you already have, through MCP, REST, and CLI.
Choose Fluxmail when agents should work in existing mailboxes, email data should stay on infrastructure you control, or each client needs narrow mailbox permissions. Choose AgentMail when every agent needs its own new address, inbound mail should arrive by webhook, and you do not want to run a server.
Feature comparison
Feature
Fluxmail
AgentMail
Mailbox model
What it is
Self-hosted email infrastructure
Hosted email provider for agents
Where mailboxes come from
Connects mailboxes you already have
Through OAuth or IMAP and SMTP credentials
Creates new inboxes through the API
On agentmail.to or a verified custom domain
Existing Gmail or Outlook mailboxes
Yes
Gmail API, Microsoft Graph, or IMAP and SMTP
Not documented
Google Workspace can route unrecognized addresses on a shared domain to AgentMail
Create inboxes on demand
No
Each mailbox is connected by a member
Yes
Inbox count depends on the plan
Deployment
Local process or Docker
Hosted by AgentMail
EU region and BYO cloud deployment on Enterprise
Where email is stored
With your email provider
Fluxmail keeps its database and encrypted credentials on your host
In AgentMail inboxes
Agent and app interfaces
MCP server
stdio and Streamable HTTP
Runs on your machine or server
Hosted server at mcp.agentmail.to
OAuth or API key, plus a stdio bridge
REST API
Versioned API with OpenAPI 3.1
API with OpenAPI 3.1
Official Python and TypeScript SDKs
CLI
Yes
Yes
Inbound events
Not built in
Clients list or search for new mail
Webhooks and WebSockets
Key permissions
Read-only, read-write, full, or custom
Plus member and mailbox allowlists
Per-key permission allowlist
Keys can be scoped to an organization, pod, or inbox
Recipient allow and block lists
Not built in
Yes
For sending, receiving, and replies
Pricing and limits
Free plan
1 member and 3 mailboxes
3 inboxes and 3,000 emails/month
Up to 100 emails a day
Paid plans
Pro $15/month; Business $25/member/month
Annual billing: Pro $120; Business $240/member
Developer $20/month; Startup $200/month
Enterprise pricing is custom
What plans limit
Members and connected mailboxes
Pro: 10 mailboxes; Business: 20 mailboxes per member
Inboxes, email volume, and storage
Developer: 10 inboxes; Startup: 150 inboxes
Sending domain
Your existing addresses
agentmail.to or a custom domain
Custom domains start on the Developer plan
A closer look
AgentMail creates inboxes and Fluxmail connects yours
AgentMail is an email provider built for agents. An API call creates a new inbox with its own address on agentmail.to or on a domain you verify, and the agent sends and receives from that identity. Its docs describe routing unrecognized addresses on a Google Workspace domain to AgentMail, but they do not describe connecting an existing Gmail or Outlook mailbox.
Fluxmail starts from the mailboxes you already use. It connects Gmail, Google Workspace, Microsoft 365, Outlook.com, and IMAP/SMTP accounts, so an agent can triage your inbox, draft replies in your threads, and send from your address. It runs on your computer or server and does not copy email content to a service operated by Fluxmail.
AgentMail pushes new mail to you and Fluxmail waits to be asked
AgentMail sends an event when a message arrives, is sent, is delivered, bounces, or draws a complaint. Webhooks need a public URL, and WebSockets deliver the same events over a persistent connection. Webhook payloads are capped at 1 MB, so for a larger message the app fetches the body through the API.
Fluxmail has no built-in inbound events. An agent or app lists or searches for new mail through MCP, REST, or the CLI when a person asks or on a schedule. That suits an assistant working in your inbox on request. An app that must react to every incoming message within seconds is a better fit for AgentMail.
AgentMail hosts the mail and Fluxmail leaves it with your provider
AgentMail runs the service and stores messages in its own inboxes. Plans limit inboxes, monthly email volume, and storage. The free plan includes 3 inboxes, 3,000 emails a month, and 3 GB. Developer costs $20 a month for 10 inboxes, and Startup costs $200 a month for 150. The EU region, BYO cloud deployment, and dedicated IPs require Enterprise.
Fluxmail runs on your computer or server. Mail stays with Gmail, Microsoft, or your IMAP provider, and Fluxmail keeps its database and encrypted credentials on your host. Plans limit members and connected mailboxes, not email volume. Personal is free for 3 mailboxes, Pro is $15 a month for 10, and Business is $25 a month per member, with 20 mailboxes per member added to the instance limit. Sending limits come from your email provider.
Which should you choose?
Best choice
Fluxmail
Agents should work in mailboxes you already have.
Mail must come from your existing Gmail, Outlook, or IMAP address.
Email data and provider credentials should stay on your infrastructure.
Each client needs its own actions and mailbox allowlist.
Plans should not cap email volume or storage.
AgentMail
Each agent needs its own new email address.
Your app reacts to inbound mail through webhooks or WebSockets.
You want a hosted service with no server to run.
Common questions
What is the best email API for AI agents?
It depends on whose mailbox the agent uses. AgentMail fits agents that need their own new inboxes, with hosted delivery and webhooks for inbound mail. Fluxmail fits agents that work in existing Gmail, Outlook, Exchange, or IMAP mailboxes from infrastructure you run.
Can AgentMail connect to my existing Gmail or Outlook inbox?
AgentMail documents new inboxes on agentmail.to or a custom domain, and a Google Workspace setup that routes unrecognized addresses on a shared domain to AgentMail. Connecting an existing Gmail or Outlook mailbox is not documented. Fluxmail connects existing mailboxes through Gmail OAuth, Microsoft Graph, or IMAP and SMTP.
Does Fluxmail have webhooks like AgentMail?
No. AgentMail delivers message events through webhooks and WebSockets. Fluxmail has no built-in inbound events, so agents and apps list or search for new mail through MCP, REST, or the CLI.
Sources
We reviewed the linked product docs on September 22, 2026.