API Overview

Base URL: https://api.mailofly.com (paths are /v1/..., e.g. https://api.mailofly.com/v1/emails)

Legacy: https://www.mailofly.com/api/v1/... on the web app remains available during migration; new integrations should use api.mailofly.com/v1/....

Quick start

# 1. Discover resources (no auth)
curl -sS "https://api.mailofly.com/v1" \
  -H "Accept: application/json"

# 2. Create an API key in the app → copy mf_live_… secret

# 3. Make an authenticated call
curl -sS "https://api.mailofly.com/v1/accounts" \
  -H "Authorization: Bearer mf_live_your_key" \
  -H "Accept: application/json"

Authentication

Header	Value
`Authorization`	`Bearer mf_live_…`
`Accept`	`application/json`
`Content-Type`	`application/json` (for POST/PATCH)

Missing or invalid keys return 401:

{
  "error": "Unauthorized",
  "message": "Invalid API key"
}

Create keys at API keys.

Response format

Success

List endpoints wrap results:

{
  "data": [ … ],
  "meta": { "page": 1, "page_size": 50, "total": 142 }
}

Single resources:

{
  "data": { "id": "uuid", "name": "…" }
}

Creates return 201 with { "data": … }.

Errors

{
  "error": "ValidationError",
  "message": "segment_id is required"
}

Code	Meaning
`400`	Invalid request body or parameters
`401`	Missing or bad API key
`403`	Insufficient role or plan limit
`404`	Resource not found in your org
`429`	Rate limit exceeded
`500`	Server error — retry with backoff

Resources

Resource	Base path	Description
Accounts	`/v1/accounts`	SMTP & Google sending identities
Segments	`/v1/segments`	Audiences
Segment contacts	`/v1/segments/{id}/contacts`	Segment membership
Contacts	`/v1/contacts`	People records
Templates	`/v1/templates`	Email content
Campaigns	`/v1/campaigns`	Campaigns, runs & send
Emails	`/v1/emails`, `/v1/emails/batch`	Resend-compatible single + batch send
Mail logs	`/v1/mail-logs`	Delivery history

Pagination

List endpoints accept:

Param	Default	Max
`page`	1	—
`page_size`	50	100

Send email (transactional)

Use GET /v1/emails to list sent transactional emails (Resend cursor: limit, after, before) or GET /v1/emails/:id to retrieve one (includes html). Send with POST /v1/emails or batch with POST /v1/emails/batch. All match Resend’s email APIs, plus optional account_key (acc_…):

POST /v1/emails
{
  "from": "Acme <onboarding@example.com>",
  "to": ["user@example.com"],
  "subject": "Hello",
  "html": "<p>Hi</p>",
  "account_key": "acc_…"
}

Optional: cc, bcc, reply_to, headers, tags, attachments, template ({ id, variables }). Returns { "id": "mail-log-uuid" }. See Emails API. The legacy /v1/compose endpoint has been removed.

Rate limits

Plan	API requests/month
Free	3,000
Basic	15,000
Scale	75,000
Enterprise	Unlimited

Each authenticated request is logged. Monitor at API usage.

Plan enforcement

API operations respect organization plan limits. Exceeding a limit returns 403 with a descriptive message:

max_accounts, max_contacts, max_templates
max_campaigns_per_month, monthly_email_quota
allow_automation, allow_google_sheet_sync

Upgrade at Billing.

Code examples

All endpoint pages include copy-paste cURL examples. Replace:

Placeholder	With
`mf_live_your_key_here`	Your API key secret
`uuid`	Actual resource ID from list/create responses
`acc_…`	Account key from Accounts page

API Reference

Sending

Receiving

Campaigns

Templates

Contacts

Domains

Webhooks

Introduction

API Overview

Quick start

Authentication

Response format

Success

Errors

Resources

Send email (transactional)

Rate limits

Plan enforcement

Code examples

​API Overview

​Quick start

​Authentication

​Response format

​Success

​Errors

​Resources

​Pagination

​Send email (transactional)

​Rate limits

​Plan enforcement

​Code examples

​Related

API Overview

Quick start

Authentication

Response format

Success

Errors

Resources

Pagination

Send email (transactional)

Rate limits

Plan enforcement

Code examples

Related