Give ChatGPT its own email address
Add Mailly to ChatGPT as a custom MCP server so ChatGPT can read your inbox, save reply drafts and send after you approve.
Add Mailly to ChatGPT as a custom MCP server and ChatGPT can search and read a real inbox, save reply drafts and send once you approve the final text. ChatGPT connects to Mailly's hosted endpoint, so there is nothing to run yourself.
What you get
- A two-way inbox on
@mailly.site, or on your own domain on the Developer plan. - About 70 Mailly tools for threads, drafts, sending, domains, contacts, templates, campaigns and workflows, limited to the permissions you grant.
- Sending under your control: ChatGPT shows the exact text and recipients, and sends only after you confirm.
Get an inbox
Already have a Mailly account? Skip to the next step.
The setup prompt needs an agent that can make HTTP requests, such as Codex. In a chat, the quickest path is mailly.site/onboard: choose a name, verify your own email and confirm the address. It's the same flow the agent setup uses.
Add Mailly as a custom MCP server
-
Open ChatGPT Plugins, select the + button and choose Add custom MCP server.
-
Enter a name (
Mailly) and a short description, for example My Mailly inbox. -
Under Connection, enter the MCP server URL, including the
/mcppath:https://mcp.mailly.site/mcp -
Set authentication to OAuth. Mailly supports ChatGPT's published client identity, so it doesn't issue you a client ID or secret.
-
Review the risk warning, select I understand and want to continue, then Create as a plugin.
-
Review the tools ChatGPT discovered.
Account and workspace policies apply to custom MCP servers. If you don't see the option, your plan or your workspace admin may not allow it.
Sign in and choose permissions
When ChatGPT asks you to connect, Mailly's sign-in and consent page opens. Choose what ChatGPT may do:
| Permission | What ChatGPT can do |
|---|---|
mail:read | Read your inboxes, threads, sent mail, drafts and settings. Always granted. |
mail:draft | Save, edit and discard reply drafts. No sending. |
mail:send | Send replies, forwards and new emails you have reviewed. |
workspace:manage | Manage addresses, domains, templates, contacts, campaigns, workflows and webhooks. |
Use it in a conversation
Start a new conversation, type @ in the prompt box and select Mailly.
Verify the connection
- Ask ChatGPT: "Use Mailly to list my inbox addresses and my five most recent threads." It should call
mailly_list_inbox_addressesandmailly_list_threads. - Send an email from your personal account to your Mailly address, then ask: "Read my latest Mailly thread and save a reply draft. Show me the exact text and don't send it." ChatGPT calls
mailly_read_threadandmailly_save_draft. - Approve the draft in the conversation if you granted
mail:send, or ask ChatGPT to discard it.
Troubleshooting
- ChatGPT doesn't use Mailly: start a new conversation and select Mailly with
@. - New Mailly tools don't show up: open the Mailly connection in ChatGPT Plugins, select Refresh, then start a new conversation.
- A tool you expected is missing: it needs a permission you didn't grant. Reconnect Mailly and grant the permission on Mailly's consent page. Mailly never widens an existing grant on its own.
- No mail arrives: check the address in the workspace and look in the inbox's Spam folder.
- A send is refused: check your balance and limits by asking ChatGPT to run
mailly_account. The Free plan allows 100 send recipients per rolling 24 hours; see pricing.
Working in a terminal or an IDE? Codex connects to the same endpoint. For every tool Mailly exposes, see Tools.