Integration · Email

Connect Claude & ChatGPT to Lettermint

Ask your AI whether an email was delivered, why it bounced, or to send a message through Lettermint. It can read messages with their delivery events, check sending stats and usage, and schedule or reschedule emails. It can also add and verify sending domains, manage projects and routes, and keep your suppression list up to date.

Connect Lettermint free

Free plan, no credit card. Takes about a minute.

Try asking

“Was the order confirmation to [email protected] delivered?”
The AI finds the message and lists its delivery events, such as delivered, opened or bounced.
“How many emails bounced last week?”
It gets sending statistics for that date range, optionally for one project.
“Send a test email from [email protected] to me.”
It sends the email with the sender, recipient, subject and body you give. The email really goes out.

What your AI can do

Send and track email

Send or schedule email, and read each message's content, status and delivery events.

Domains and projects

Add and verify sending domains, and create or update projects and read their routes.

Suppressions and stats

Manage the suppression list and check sending stats, usage and team details.

“Add mail.ourdomain.com as a sending domain.”
It adds the domain and returns the DNS records to set up, then checks them when you are ready.
“Stop sending to this address, they asked to be removed.”
It adds the address to the suppression list with the scope and reason you choose.
“Move tomorrow's scheduled newsletter to Friday at 8:00.”
It changes when the scheduled email goes out.

50 tools for Lettermint

These tools are switched on when you connect. You can switch any of them off, or require your approval before it runs.

add_domainChanges dataAdd a sending `domain`. Afterwards add the DNS records it returns and run verify_domain_dns.
add_suppressionChanges dataStop sending to an `email` (or several `emails`) by adding them to the suppression list, with a `scope` (team, project or route) and `reason`.
cancel_messageDeletesCancel a scheduled email by `message_id` so it is not sent. This cannot be undone.
create_batchDeletesCreate a new batch. Destructive action; may require approval. API summary: Send multiple emails in a batch.
create_message_processVisible to othersCreate a new process for a message. Has effects visible outside this system. API summary: Process one quarantined inbound message.
create_projectChanges dataCreate a project with a `name`, optionally choosing its starting routes (transactional, broadcast or both).
create_project_routeChanges dataCreate a new route for a project. Required: name or route type. Search routes first to avoid duplicates.
create_webhookDeletesCreate a new webhook. Required: name, url or events. Search webhooks first to avoid duplicates. Destructive action; may require approval.
create_webhook_regenerate_secretDeletesCreate a new regenerate secret for a webhook. Destructive action; may require approval. API summary: Regenerate webhook secret.
create_webhook_testDeletesCreate a new test for a webhook. Destructive action; may require approval. API summary: Test a webhook by sending a sample payload.
delete_domainDeletesPermanently delete a domain by domain id. Destructive action; may require approval.
delete_projectDeletesPermanently delete a project by project id. Destructive action; may require approval.
delete_routeDeletesPermanently delete a route by route id. Destructive action; may require approval.
delete_webhookDeletesPermanently delete a webhook by webhook id. Destructive action; may require approval.
get_domainGet one sending domain by `domain_id`, including the DNS records to set up and their status.
get_messageGet one email by `message_id`, with sender, recipients, subject and delivery status.
get_message_htmlGet the HTML body of an email by `message_id`.
get_message_textGet the plain-text body of an email by `message_id`.
get_projectGet one project by `project_id`.
get_routeGet one route by `route_id`.
get_statsGet sending statistics (sent, delivered, opened, bounced and so on) between `from` and `to` dates, optionally for one project.
get_teamGet your Lettermint team details.
get_usageGet your team's current email usage.
get_userGet one user by user id. API summary: Get a team member.
get_webhookGet one webhook by webhook id. API summary: Get webhook details.
get_webhook_shipmentGet one shipment for a webhook by shipment id. API summary: Get a specific webhook delivery.
list_blocked_file_typesList blocked file types.
list_domainsList your sending domains, optionally filtered by domain name, verification status or project.
list_message_eventsList the delivery events for an email (queued, delivered, opened, clicked, bounced and so on) by `message_id`.
list_message_sourcesList sources for a message. API summary: Get message source.
list_messagesList sent and received emails, filtered by status, subject, recipient search, tag, project, domain or date range.
list_project_routesList the routes (transactional, broadcast, inbound) of a project by `project_id`.
list_projectsList your projects (each has its own sending routes and token), optionally filtered by name.
list_rolesList roles. API summary: Get reusable team roles.
list_suppressionsList suppressed email addresses (bounces, complaints, unsubscribes), filterable by reason, value, project or date.
list_usersList users. Results are paginated. API summary: Get team members.
remove_suppressionDeletesRemove an address from the suppression list by `suppression_id`, so it can receive email again.
reschedule_messageVisible to othersChange when a scheduled email goes out by `message_id`, passing a new `scheduled_at`.
search_webhook_shipmentsSearch shipments for a webhook by sort, filter status, filter event type, filter from date or filter to date. Use this to find existing shipments before creating a new shipment. API summary: Get webhook deliveries.
search_webhooksSearch webhooks by sort, filter project, filter enabled, filter event, filter route id or filter scope. Use this to find existing webhooks before creating a new webhook. API summary: List all webhooks for the team.
send_emailVisible to othersSend an email: `from`, `to`, `subject` and an `html` or `text` body, plus optional cc, bcc, reply-to, tags and attachments. Set `scheduled_at` to send later. The email really goes out.
submit_dns_record_verifyVisible to othersVerify a dns record (record id). Has effects visible outside this system. API summary: Verify a specific DNS record.
submit_route_inbound_domainVisible to othersVerify a route (route id). Has effects visible outside this system. API summary: Verify inbound domain for a route.
update_domain_projectsVisible to othersUpdate an existing project identified by domain id. Has effects visible outside this system. API summary: Update projects associated with a domain.
update_projectChanges dataUpdate a project's name, default route or settings by `project_id`. Only the fields you pass change.
update_routeChanges dataUpdate an existing route identified by route id. API summary: Update route settings.
update_teamsVisible to othersUpdate an existing team. Has effects visible outside this system. API summary: Update team settings.
update_user_assignmentsVisible to othersUpdate an existing assignment identified by user id. Has effects visible outside this system. API summary: Replace a team member's assignment.
update_webhookDeletesUpdate an existing webhook identified by webhook id. Destructive action; may require approval. API summary: Update webhook settings.
verify_domain_dnsVisible to othersCheck all DNS records of a domain by `domain_id` to verify it for sending.

Set up in three steps

1
Pick the app
Create a free HeyMyApps account and choose Lettermint from the app list.
2
Paste your key
Paste two tokens. Create a Team API token in your Lettermint team settings (it starts with lm_team_); it is used for domains, projects, messages and suppressions. Then open the project you send from and copy its Project API token (it starts with lm_) from the project settings; it is used for sending email.
3
Add the link to your AI
You get a personal MCP link. Add it to Claude, ChatGPT or Cursor:
1. Click your name, then Settings › Connectors › Add custom connector.
2. Paste your link as the Remote MCP server URL.
3. Switch it on from the + menu in a chat.

Questions

What can the AI do in Lettermint?

The AI can read messages with their HTML or text body and delivery events, domains, projects, routes, suppressions, sending stats, usage and your team. It can send, schedule, reschedule and cancel email, add and verify domains, create and update projects, and add or remove suppressions.

Does the AI see my Lettermint API tokens?

No. Your Lettermint tokens are encrypted at rest and never shown to the AI. After you save them, they are not shown again, not even to you. The AI only sees the results of the tools it calls.

Can I control what the AI is allowed to do?

Yes. You choose which tools are switched on, so you can start with reading messages and stats. Sending email reaches real recipients, and cancelling a scheduled email or removing a suppression cannot be undone, so these can require your approval before they run. Every tool call is logged.

Does it work with ChatGPT?

Yes. In ChatGPT go to Settings › Apps & Connectors › Advanced and turn on Developer mode, then add your HeyMyApps link. Developer mode needs a paid ChatGPT plan: Plus, Pro, Business or Enterprise. The same link also works in Claude (Settings › Connectors › Add custom connector), Cursor and other MCP clients.

What does it cost?

HeyMyApps has a free plan with no credit card required. Paid plans bill per completed task. You also need your own Lettermint account.

Why does Lettermint need two tokens?

Lettermint uses a Team API token for managing your team's domains, projects, messages and suppressions, and a Project API token for sending email from a specific project. You paste both into HeyMyApps, and each tool uses the one it needs.