Postmark Automation via Rube MCP

Automate Postmark transactional email operations through Composio’s Postmark toolkit via Rube MCP.

Prerequisites

• Rube MCP must be connected (RUBE_SEARCH_TOOLS available)
• Active Postmark connection via RUBE_MANAGE_CONNECTIONS with toolkit postmark
• Always call RUBE_SEARCH_TOOLS first to get current tool schemas

Setup

Get Rube MCP: Add https://rube.app/mcp as an MCP server in your client configuration. No API keys needed — just add the endpoint and it works.

1. Verify Rube MCP is available by confirming RUBE_SEARCH_TOOLS responds
2. Call RUBE_MANAGE_CONNECTIONS with toolkit postmark
3. If connection is not ACTIVE, follow the returned auth link to complete Postmark authentication
4. Confirm connection status shows ACTIVE before running any workflows

Core Workflows

1. Send Templated Batch Emails

When to use: User wants to send templated emails to multiple recipients in one call

Tool sequence:

1. POSTMARK_LIST_TEMPLATES – Find available templates and their IDs [Prerequisite]
2. POSTMARK_VALIDATE_TEMPLATE – Validate template with model data before sending [Optional]
3. POSTMARK_SEND_BATCH_WITH_TEMPLATES – Send batch emails using a template [Required]

Key parameters:

• TemplateId or TemplateAlias: Identifier for the template to use
• Messages: Array of message objects with From, To, TemplateModel
• TemplateModel: Key-value pairs matching template variables

Pitfalls:

• Maximum 500 messages per batch call
• Either TemplateId or TemplateAlias is required, not both
• TemplateModel keys must match template variable names exactly (case-sensitive)
• Sender address must be a verified Sender Signature or from a verified domain

2. Manage Email Templates

When to use: User wants to create, edit, or inspect email templates

Tool sequence:

1. POSTMARK_LIST_TEMPLATES – List all templates with IDs and names [Required]
2. POSTMARK_GET_TEMPLATE – Get full template details including HTML/text body [Optional]
3. POSTMARK_EDIT_TEMPLATE – Update template content or settings [Optional]
4. POSTMARK_VALIDATE_TEMPLATE – Test template rendering with sample data [Optional]

Key parameters:

• TemplateId: Numeric template ID for GET/EDIT operations
• Name: Template display name
• Subject: Email subject line (supports template variables)
• HtmlBody: HTML content of the template
• TextBody: Plain text fallback content
• TemplateType: ‘Standard’ or ‘Layout’

Pitfalls:

• Template IDs are numeric integers, not strings
• Editing a template replaces the entire content; include all fields you want to keep
• Layout templates wrap Standard templates; changing a layout affects all linked templates
• Validate before sending to catch missing variables early

3. Monitor Delivery Statistics

When to use: User wants to check email delivery health, open/click rates, or outbound overview

Tool sequence:

1. POSTMARK_GET_DELIVERY_STATS – Get bounce counts by type [Required]
2. POSTMARK_GET_OUTBOUND_OVERVIEW – Get sent/opened/clicked/bounced summary [Required]
3. POSTMARK_GET_TRACKED_EMAIL_COUNTS – Get tracked email volume over time [Optional]

Key parameters:

• fromdate: Start date for filtering stats (YYYY-MM-DD)
• todate: End date for filtering stats (YYYY-MM-DD)
• tag: Filter stats by message tag
• messagestreamid: Filter by message stream (e.g., ‘outbound’, ‘broadcast’)

Pitfalls:

• Date parameters use YYYY-MM-DD format without time component
• Stats are aggregated; individual message tracking requires separate API calls
• messagestreamid defaults to all streams if not specified

4. Manage Bounces and Complaints

When to use: User wants to review bounced emails or spam complaints

Tool sequence:

1. POSTMARK_GET_BOUNCES – List bounced messages with details [Required]
2. POSTMARK_GET_SPAM_COMPLAINTS – List spam complaint records [Optional]
3. POSTMARK_GET_DELIVERY_STATS – Get bounce summary counts [Optional]

Key parameters:

• count: Number of records to return per page
• offset: Pagination offset for results
• type: Bounce type filter (e.g., ‘HardBounce’, ‘SoftBounce’, ‘SpamNotification’)
• fromdate/todate: Date range filters
• emailFilter: Filter by recipient email address

Pitfalls:

• Bounce types include: HardBounce, SoftBounce, SpamNotification, SpamComplaint, Transient, and others
• Hard bounces indicate permanent delivery failures; these addresses should be removed
• Spam complaints affect sender reputation; monitor regularly
• Pagination uses count and offset, not page tokens

5. Configure Server Settings

When to use: User wants to view or modify Postmark server configuration

Tool sequence:

1. POSTMARK_GET_SERVER – Retrieve current server settings [Required]
2. POSTMARK_EDIT_SERVER – Update server configuration [Optional]

Key parameters:

• Name: Server display name
• SmtpApiActivated: Enable/disable SMTP API access
• BounceHookUrl: Webhook URL for bounce notifications
• InboundHookUrl: Webhook URL for inbound email processing
• TrackOpens: Enable/disable open tracking
• TrackLinks: Link tracking mode (‘None’, ‘HtmlAndText’, ‘HtmlOnly’, ‘TextOnly’)

Pitfalls:

• Server edits affect all messages sent through that server
• Webhook URLs must be publicly accessible HTTPS endpoints
• Changing SmtpApiActivated affects SMTP relay access immediately
• Track settings apply to future messages only, not retroactively

Common Patterns

Template Variable Resolution

1. Call POSTMARK_GET_TEMPLATE with TemplateId
2. Inspect HtmlBody/TextBody for {{variable}} placeholders
3. Build TemplateModel dict with matching keys
4. Call POSTMARK_VALIDATE_TEMPLATE to verify rendering

Pagination

• Set count for results per page (varies by endpoint)
• Use offset to skip previously fetched results
• Increment offset by count each page until results returned < count
• Total records may be returned in response metadata

Known Pitfalls

Authentication:

• Postmark uses server-level API tokens, not account-level
• Each server has its own token; ensure correct server context
• Sender addresses must be verified Sender Signatures or from verified domains

Rate Limits:

• Batch send limited to 500 messages per call
• API rate limits vary by endpoint; implement backoff on 429 responses

Response Parsing:

• Response data may be nested under data or data.data
• Parse defensively with fallback patterns
• Template IDs are always numeric integers

Quick Reference