Mailsso MCP server

Connect Mailsso to Claude, ChatGPT, Cursor, Claude Code, Codex, Gemini, GitHub Copilot and any other MCP client, for your whole team. Metorial adds security, governance, and tracing, and gives everyone one Magic MCP URL to connect.

What you can do with the Mailsso MCP server

Ask your agent in plain language. Each of these maps to a real tool on the server.

  • Use the get bulk validation results tool in Mailsso
  • Use the bulk validate emails tool in Mailsso
  • Use the validate email tool in Mailsso
  • Use the export bulk validation results tool in Mailsso

Supported Tools

get_bulk_validation_results

Get Bulk Validation Results

Retrieve the status and results of a bulk email validation batch job. Returns whether the job has finished, and if complete, includes the full validation results for each email in the batch.

bulk_validate_emails

Bulk Validate Emails

Submit a list of email addresses for bulk validation. This starts an asynchronous batch job and returns the batch ID, which can be used to poll for results using the **Get Bulk Validation Results** tool. Requires a paid Mails.so subscription.

validate_email

Validate Email

Validate a single email address in real time. Returns a deliverability classification (`deliverable`, `undeliverable`, `risky`, or `unknown`), a validity score from 0–100, and detailed checks including format validity, domain validity, MX records, blocklist status, catch-all detection, and free provider detection.

export_bulk_validation_results

Export Bulk Validation Results

Download a completed bulk email validation job as a JSON file containing every email result, validation ID, score, reason, and check. Useful for archiving a validated list or importing it into another system.

Connect Mailsso to your AI client

Every client uses the same Magic MCP URL, and so does any other MCP client. Add it once and sign in with SSO.

  1. Enable Mailsso in Metorial. In your Metorial portal, enable the Mailsso MCP server and sign in with the account that owns the data. Access stays governed by your team policies.
  2. Add a custom connector. Open Customize, then Connectors. Select Add, then Custom, then Web.
  3. Paste your Metorial MCP URL. Name it Metorial, paste your Magic MCP URL (<your-magic-mcp-url>) and continue.
  4. Sign in. Select Add and sign in to load Mailsso tools.

Run Mailsso through the Metorial gateway

One governed layer for every app your agents reach, not a separate connector per tool.

  • Give Mailsso and every other app to your whole team through one MCP gateway, behind your SSO.
  • Scope which teams and agents can use Mailsso tools with role-based access control, and trace every call.
  • Prefer to run it yourself? Metorial is open source and self-hostable.

More integrations teams use with Mailsso

Slack

Slack: connect with bot OAuth or user OAuth to work with messages, conversations, search, files, Canvases, Lists, profiles, reactions, reminders, and workspace productivity settings.

Salesforce

Manage CRM data including Accounts, Contacts, Leads, Opportunities, Cases, and custom objects. Create, read, update, and delete records. Query data using SOQL and search across objects using SOSL. Perform bulk data operations for large-scale imports, exports, and migrations. Execute composite requests to batch multiple operations in a single API call. Access analytics, reports, and dashboards. Manage files and attachments associated with records. Interact with Chatter feeds, posts, and groups for social collaboration. Manage org metadata including custom objects, fields, layouts, and workflows. Query data using GraphQL for precise data retrieval across related objects.

Apolloio

Search and prospect B2B contacts and companies from a database of over 275 million people and 70 million organizations. Enrich people and company data with emails, phone numbers, and firmographic details. Create and manage contacts, accounts, deals, and tasks. Add contacts to email sequences and manage sequence statuses. Log and search call records. Perform bulk operations for contact creation, account creation, task creation, and data enrichment.

Sharepoint

Manage SharePoint sites, document libraries, lists, and files. Create, read, update, and delete lists and list items with custom columns. Resolve site users to numeric Person/Group LookupId values. Upload, download, move, copy, and version files in document libraries. Search across sites, files, folders, lists, and list items using Microsoft Search. Manage permissions at site, list, and item levels with granular access control. Define and manage content types and site columns. Retrieve site properties and search for sites across Microsoft 365.

Microsoft Outlook

Send, read, reply to, forward, and manage email messages in user mailboxes. Organize messages into folders, apply categories, flags, and importance levels. Manage file and item attachments. Create, update, delete, and respond to calendar events and meetings. Find available meeting times, manage attendees, handle recurrence, and work with shared or delegated calendars. Create, read, update, and delete contacts, organize them into contact folders, and manage contact photos. Manage tasks and task lists via Microsoft To Do, including due dates, reminders, recurrence, and checklist items. Support for Focused Inbox, @-mentions, mail tips, send-on-behalf, and send-as capabilities.

Hubspot

Create, read, update, and delete CRM objects including contacts, companies, deals, tickets, and custom objects. Manage associations between CRM records. Track engagements such as calls, emails, meetings, notes, and tasks. Send transactional and marketing emails, manage campaigns, and handle subscription preferences. Build and manage marketing workflows, sequences, and automation actions. Manage CMS content including blog posts, landing pages, and HubDB tables. Handle commerce data including products, orders, invoices, quotes, and payments. Create and manage contact lists for segmentation. Configure deal, ticket, and order pipelines with custom stages. Search and filter CRM records. Bulk import and export CRM data. Manage users, teams, and account settings.

Technical notes for Mailsso

Validate and verify email addresses for deliverability and quality. Check individual emails or bulk-validate lists for format validity, domain and MX record status, catch-all policies, disposable address detection, and blocklist presence. Returns deliverability scores and classifications to help maintain clean email lists. Download completed bulk results as JSON for archiving or import into another system.

Frequently asked questions

Common questions about connecting Mailsso to AI agents with Metorial.

  1. How many tools does the Mailsso MCP server have?
    The Mailsso MCP server exposes 4 tools, including Get Bulk Validation Results, Bulk Validate Emails, Validate Email. Each one is governed and traced through Metorial.
  2. Mailsso exposes tools your agents call on demand; it does not publish event triggers yet. Everything still runs through one governed MCP URL.
  3. Any MCP client, including VS Code, Windsurf, Zed, OpenCode and Grok. Each one reaches the Mailsso MCP server through the same Metorial URL.
  4. Use role-based access control to decide which teams, users, and agents can use Mailsso and which of its tools they can call.
  5. Yes. Metorial is open source, so you can run the Mailsso MCP server yourself or use the hosted gateway.

Connect Mailsso to production AI agents

See how Metorial gives your team governed access to Mailsso, with tracing and security controls built in.