MailerSend
MailerSend is a transactional email service designed for developers to integrate email sending capabilities into their applications.
Verdict
Common use cases
- Provision sending domains during app deployment
- Generate SMTP credentials for staging environments
- Configure delivery webhooks for event tracking
- Audit API token permissions across projects
- Monitor rate limits before campaign launches
Integration
- Vendor
- MailerSend
- Category
- other
- Auth
- API_KEY
- Tools
- 23
- Composio slug
mailersend
Tools
- Create API Token
Tool to create a new api token. use when you need to generate a token with specific permissions in mailersend.
- Create Sending Domain
Tool to add a new sending domain to mailersend. use when you need to register and configure a domain before sending emails.
- Create SMTP User
Tool to create a new smtp user. use after domain setup to obtain smtp credentials.
- Create Webhook
Tool to create a new webhook for a mailersend domain. use after you have a domain id and need to receive event notifications like sent, delivered, opened, etc.
- Delete Webhookdestructive
Tool to delete an existing webhook. use when the webhook is no longer needed. returns empty response on successful deletion (http 204).
- Get API Quota
Tool to retrieve current api usage quota. use when monitoring api rate limits to avoid exceeding allowed calls.
- Get API Tokens
Tool to retrieve a list of api tokens. use when you need to list and paginate api tokens after authentication.
- Get Domain
Tool to fetch information for a specific sending domain. use when you need to verify domain status and dns configuration after setup or changes.
- Get email recipients
Tool to retrieve a list of email recipients. use when you need to list and filter recipients by list id or search term.
- Get email templates
Tool to retrieve a list of email templates. use when you need to list and paginate email templates.
- Get general API resources
Tool to retrieve general api resources and information. use when you need an overview of all mailersend endpoints before constructing specific calls.
- Get sending domains
Tool to retrieve a list of sending domains. use after configuring the mailersend api key.
- Get sent messages
Tool to retrieve a paginated list of sent messages. use after sending emails to view message logs.
- Get SMS Activity
Tool to retrieve sms activity logs. use when you need to fetch delivery status and logs of sent sms messages.
- Get SMS Inbounds
Tool to retrieve inbound sms messages. use when you need to fetch sms messages received on your mailersend numbers.
- Get SMS Numbers
Tool to retrieve a paginated list of sms phone numbers. use after purchasing numbers to fetch available sms numbers.
- Get SMS recipients
Tool to retrieve a list of sms recipients. use when you need to list and paginate sms recipients, optionally filtering by sms number id.
- Get SMTP users
Tool to retrieve a list of smtp users. use when you need to list and paginate smtp users.
- Get users
Tool to retrieve a list of users associated with your account. use after authenticating with a valid api token.
- List Domain Recipients
Tool to list recipients for a domain. use after obtaining the domain id to view recipients with optional pagination.
- List Sender Identities
Tool to list sender identities. use when you need to retrieve all configured email or domain sender identities after authenticating with your mailersend api token.
- List SMS Messages
Tool to list sent sms messages with optional filters. use after sending sms to review message logs.
- List webhooks
Tool to retrieve a list of webhooks. use when you need to list and paginate all configured webhooks, optionally filtering by domain.
Setup
Setup guide
- 11. In Switchy, open the Space where you want email infrastructure tools available. 2. Click 'Add Integration' and select MailerSend from the MCP directory. 3. You'll be prompted for a MailerSend API key — generate one at mailersend.com under API Tokens with 'Domains', 'SMTP Users', 'Webhooks', and 'Tokens' scopes enabled. 4. Paste the key into Switchy and click 'Connect'. 5. Test the connection by typing '@MailerSend get my API quota' in the Space chat — you should see your current rate limit and usage. 6. To invoke other tools, @mention MailerSend followed by a task like 'create a sending domain for example.com' or 'list my webhooks'. The MCP returns structured data you can review or pass to follow-up prompts.
What teammates see: by default, memories from MailerSend are scoped to the Space (PROJECT visibility) - you can mark any memory PRIVATE or share it ORG-wide.
Works well with
Top models
Compatibility data appears once enough Spaces have used this MCP together with a given model.
How Switchy teams use it
Starter prompts
Add Sending Domain
@MailerSend create a sending domain for notifications.myapp.com and show me the DNS records I need to add.Open in a Space →
Generate SMTP Credentials
@MailerSend create an SMTP user for my domain notifications.myapp.com and give me the username and password.Open in a Space →
Set Up Delivery Webhook
@MailerSend create a webhook for domain notifications.myapp.com that posts delivery events to https://api.myapp.com/hooks/email.Open in a Space →
Check API Quota
@MailerSend get my API quota and tell me how many calls I have left this month.Open in a Space →
Verify Domain Status
@MailerSend get the status of my domain notifications.myapp.com and confirm the DNS records are verified.Open in a Space →
Example outputs
Illustrative - representative of the model's voice and quality, not literal recordings.
@MailerSend check my current API quota and tell me how close I am to hitting limits this month
Your MailerSend account has used 14,287 of 50,000 monthly email sends (28.6% utilized). You have 35,713 sends remaining. Your current plan resets on March 1st. At your current pace (approximately 475 sends per day), you're projected to use roughly 43% of your quota by month-end, leaving comfortable headroom.
This example shows read-only monitoring of account health. Requires a valid API key with quota-read permissions. Useful for proactive capacity planning before campaigns, though quota data may lag by up to 15 minutes during high-volume periods.
@MailerSend create a webhook for domain_id dm_abc123 that listens for email.delivered and email.opened events and posts to https://api.myapp.com/mailhook
Webhook created successfully for domain dm_abc123. It will now send POST requests to https://api.myapp.com/mailhook whenever emails are delivered or opened. Webhook ID: wh_xyz789. Remember to validate the webhook signature in your endpoint using the MailerSend signing secret to ensure requests are authentic.
This demonstrates MailerSend's event-driven integration capability. Requires domain ownership and a publicly accessible HTTPS endpoint. The webhook will immediately start firing for matching events—ensure your endpoint can handle the volume and has proper authentication checks before creating in production.
@MailerSend I need to set up a new sending domain for newsletter.acme.com — walk me through adding it and show me what DNS records I need to configure
Domain newsletter.acme.com has been added to your MailerSend account (domain ID: dm_new456). To verify ownership and enable sending, add these DNS records at your domain registrar: • TXT record: _mailersend.newsletter.acme.com → ms-verify=abc123def456 • CNAME: mail._domainkey.newsletter.acme.com → mail._domainkey.u12345.wl.senderscore.com • MX: newsletter.acme.com → feedback.mailersend.net (priority 10) DNS propagation typically takes 15 minutes to 48 hours. Check verification status with the Get Domain tool after your records are live.
This example shows the multi-step domain setup workflow. Creating the domain is instant, but verification depends on external DNS propagation—the MCP cannot complete this automatically. Users must have registrar access to add records. Domain verification is required before any emails can be sent from this address.
Use-case deep-dives
When MailerSend fits early-stage product teams sending user emails
A 5-person SaaS team shipping password resets, welcome sequences, and trial-expiry notices needs reliable delivery without hiring a deliverability engineer. MailerSend wins here because the MCP exposes domain setup, SMTP credential creation, and webhook registration in one place—your AI can walk you through DNS records, test a send, and wire up open/bounce tracking in a single conversation. The API quota tool matters when you're scaling from 100 to 10k emails a month and need to catch rate-limit warnings before users see failures. The threshold: if you're sending marketing campaigns or need advanced segmentation, you'll outgrow this fast and want a dedicated ESP. For transactional flows under 50k sends a month, this MCP removes the friction of stitching together docs and dashboards. Set up your first domain in Switchy, let the AI generate SMTP credentials, and ship onboarding emails this afternoon.
Why MailerSend works for support teams automating email alerts
A 3-person support team at a B2B tool wants to send ticket-assigned and ticket-resolved emails to customers without building a notification service from scratch. MailerSend handles this because the webhook tooling lets you subscribe to delivery events (sent, bounced, complained) and feed them back into your support system—so you know when a customer didn't get the resolution email and can follow up manually. The MCP's token management tools matter here because support workflows often run on separate API keys with scoped permissions, and you don't want one broken integration to lock the whole team out. The catch: if you're routing more than basic transactional alerts or need conditional logic inside the email (like dynamic ticket links), you'll spend time in MailerSend's template editor, which the MCP doesn't touch. For straightforward ticket notifications under 5k a month, configure webhooks in Switchy and stop wondering if emails landed.
When this MCP speeds up multi-client email setup for agencies
A 4-person dev shop onboards 8 clients a quarter, each needing a sending domain, SMTP credentials, and webhook endpoints wired to their app. MailerSend's MCP collapses the setup checklist into a repeatable AI conversation: create domain, verify DNS, generate SMTP user, register webhook, check quota—all without context-switching between client dashboards. The domain-fetching tool is the quiet MVP here because DNS propagation is the usual blocker, and you can poll status in Switchy instead of refreshing the MailerSend UI. The limit: if a client needs white-label sender addresses or complex suppression lists, you're back in the web console anyway. For agencies running 5-15 client email setups a year, this MCP turns a 45-minute checklist into a 10-minute guided session. Onboard your next client's email stack in Switchy and bill the saved hours.
Frequently asked
What does the MailerSend MCP let me do in Switchy?
It connects your MailerSend account so AI can manage your transactional email infrastructure — creating domains, SMTP users, webhooks, and API tokens without you opening the dashboard. Useful when you're setting up a new app environment or debugging delivery issues and want the AI to check DNS records, quota limits, or webhook configs on the fly.
Do I need admin access to connect MailerSend?
You need an API key with the scopes matching what you want the AI to do. MailerSend lets you create tokens with granular permissions (domains, tokens, webhooks, SMTP users). If you only want read-only quota checks, a restricted key works. For full setup automation, generate a key with write access to domains and webhooks before connecting.
Can the MCP actually send emails through MailerSend?
No. This MCP manages your MailerSend infrastructure — domains, SMTP credentials, webhooks, tokens — but doesn't send messages. To send email, your app uses the SMTP user or API credentials the MCP creates. Think of it as the setup layer, not the sending layer. For one-off sends, use MailerSend's dashboard or API directly.
Why use this instead of just logging into MailerSend?
Speed when you're spinning up environments or troubleshooting. Instead of clicking through five dashboard screens to add a domain, verify DNS, create an SMTP user, and set up a webhook, you tell the AI "set up staging.example.com for transactional email" and it chains the tools. Saves ten minutes per domain, especially useful for agencies managing multiple client accounts.
Who on the team should connect this MCP?
Whoever owns your email infrastructure — usually a backend dev or DevOps engineer. They already have MailerSend API access and understand domain verification. Marketing team members who only send campaigns through MailerSend's UI won't need this; it's for people automating setup tasks or debugging delivery at the API level.