The best Nylas alternative for an AI agent that works in your own or your team's mailboxes is Fluxmail, which connects Gmail, Outlook, and IMAP over MCP and REST, hosted or self-hosted, with flat plan prices instead of a fee for each connected account. For a self-hosted API that connects many accounts, use EmailEngine. If your product connects your customers' Gmail and Outlook accounts along with other apps, use Composio. For agents that need their own new addresses, use AgentMail.
Nylas prices by connected account and is built for products whose customers connect their email, calendar, and contacts. That's more than many agent projects need, and its MCP server authenticates with a Nylas API key and needs each mailbox connected to Nylas first. Nylas details come from our Fluxmail vs Nylas comparison, reviewed October 22, 2026, which links to Nylas's own docs. Details on the other products come from their docs and pricing pages, read the same day.
What should I look for in a Nylas alternative?
Start with whose mailboxes the agent uses:
- Your own or your team's existing mailboxes: you need a server that connects to Gmail, Microsoft, and IMAP and lets you limit each agent's permissions.
- Your customers' mailboxes, inside a product you're building: you need per-user OAuth, and probably webhooks.
- New mailboxes that belong to the agent: you need a service that creates inboxes, not one that connects them.
Then check the interfaces your agent can use (MCP, REST, or SDKs), whether you want it hosted or on your own server, and how the price grows as you add mailboxes.
What are the best Nylas alternatives for AI agents?
We make Fluxmail, so it's listed first. EmailEngine and Composio connect existing mailboxes, as Nylas does. AgentMail creates new ones.
1. Fluxmail
Fluxmail connects agents to your own or your team's Gmail, Outlook, Exchange, or IMAP mailboxes. Fluxmail Cloud hosts an MCP server at https://cloud.fluxmail.ai/mcp and a REST API for scripts. Claude, ChatGPT, Cursor, and other MCP clients sign in with OAuth, and you approve the mailboxes and permissions each one gets: Read only, Read and write, or Full mail access. Self-hosted Fluxmail runs the same tools on your own machine or in Docker, adds a CLI and scheduled sending, and keeps credentials on your server.
Compared with Nylas, Fluxmail is email only, with no calendar, contacts, or meeting notes, and it has no inbound webhooks. Gmail setup is simpler, though: Cloud and self-hosted Fluxmail on your own computer don't need your own Google Cloud project or Google's security assessment. Cloud connects Gmail through Fluxmail's Google app, and local self-hosted setups use a bundled Google client. A self-hosted server with a public callback uses your own Google app.
Self-hosted is free for one member and three mailboxes. Pro is $15 a month for ten mailboxes and Business is $25 per member a month, in Cloud or self-hosted.
2. EmailEngine
EmailEngine is a self-hosted gateway for apps that connect many accounts and react to webhooks. It connects IMAP and SMTP accounts and has native Gmail API and Microsoft Graph integrations. Like Nylas, it sends signed webhooks when mail arrives or changes, queues sends, and supports templates and mail merge. It needs Redis. Its MCP endpoint has been in beta since August 2026 and stays off until an administrator enables it.
It costs $1,450 a year, excluding VAT, for unlimited instances and IMAP accounts, after a 14-day trial. A flat price can cost less than per-account pricing once you connect many accounts. The Fluxmail vs EmailEngine comparison covers the differences in detail.
3. Composio
Composio is a hosted integration platform for products whose users connect Gmail or Outlook alongside many other apps. It has separate Gmail and Outlook toolkits, with 63 and 328 tools (the Outlook count includes calendar and contacts). Composio can manage OAuth for you, and each user gets a hosted MCP session URL. That's the closest match here to Nylas's model of connecting your users' accounts, though each provider has its own tools instead of one shared email API.
With your own OAuth app, the Hobby plan is free with 100,000 tool calls a month and unlimited connected accounts. Pro is $29 a month, which includes $29 of usage credit, then $0.0003 per tool call. Composio's managed OAuth apps cost more: only 20,000 of the 100,000 free tool calls cover them, after which each call costs $0.0005. The first 1,000 managed connections are free, and on paid plans each additional one costs a one-time $0.10. See Fluxmail vs Composio Gmail.
4. AgentMail
AgentMail is a hosted email provider for agents that need their own address. It's the one to look at if you use Nylas Agent Accounts, which create inboxes on your own domain. An API call creates an inbox on agentmail.to or, from the Developer plan up, on your domain, and new mail arrives by webhook or WebSocket. It has a hosted MCP server with OAuth or API key sign-in. AgentMail doesn't document connecting existing Gmail or Outlook mailboxes.
It's free for 3 inboxes and 3,000 emails a month. Developer is $20 a month for 10 inboxes, and Startup is $200 a month for 150. Fluxmail vs AgentMail explains when each fits.
When is Nylas still the right choice?
Stay with Nylas if your product connects many customers' accounts and needs calendar, contacts, scheduling, or meeting notes alongside email. It also fits when you want a hosted service with US and EU regions, webhooks through Pub/Sub or SNS, and SDKs. None of the alternatives above covers all of that in one API.
How do the prices compare?
| Product | Free option | Paid pricing |
|---|---|---|
| Nylas | 5 connected accounts | Essentials $15 a month for 10 accounts, then $2.25 each; Pro $49 a month for 25, then $2.00 each |
| Fluxmail | Self-hosted: 1 member, 3 mailboxes; Cloud: 7-day trial | Pro $15 a month for 10 mailboxes; Business $25 per member a month |
| EmailEngine | 14-day trial | $1,450 a year, unlimited accounts |
| Composio | 100,000 tool calls a month | Pro $29 a month plus usage |
| AgentMail | 3 inboxes, 3,000 emails a month | Developer $20 a month; Startup $200 a month |
Frequently asked questions
Is there a free Nylas alternative?
Yes. Self-hosted Fluxmail is free for one member and three mailboxes. Composio's Hobby plan and AgentMail's free plan are hosted options with usage limits.
Which Nylas alternative has an MCP server?
All four. Fluxmail Cloud, Composio, and AgentMail host MCP servers. Self-hosted Fluxmail serves MCP from your own machine, and EmailEngine's MCP endpoint is in beta.
Do I need Google verification to connect Gmail?
With Nylas and your own Google Cloud project, apps that read Gmail need Google verification and a security assessment, unless they're for personal use with fewer than 100 users or internal to your Workspace. Fluxmail Cloud and Composio's managed OAuth connect through their own Google apps. Self-hosted Fluxmail bundles a Google client for local setups.
Which alternative works with Claude and ChatGPT?
Fluxmail Cloud and AgentMail both have hosted MCP servers with OAuth that you add in Claude or ChatGPT. Self-hosted Fluxmail works too once it's on a public HTTPS URL. How to connect Gmail or Outlook to Claude, ChatGPT and Cursor shows the steps for Fluxmail.
Can I replace Nylas calendar and contacts too?
Mostly not. Fluxmail and EmailEngine cover email only, and AgentMail's calendar is only for its own inboxes. Composio comes closest: its Outlook toolkit includes calendar and contacts, and Google Calendar is a separate toolkit.