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_CONNECTIONSwith toolkitpostmark - •Always call
RUBE_SEARCH_TOOLSfirst 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.
- •Verify Rube MCP is available by confirming
RUBE_SEARCH_TOOLSresponds - •Call
RUBE_MANAGE_CONNECTIONSwith toolkitpostmark - •If connection is not ACTIVE, follow the returned auth link to complete Postmark authentication
- •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:
- •
POSTMARK_LIST_TEMPLATES- Find available templates and their IDs [Prerequisite] - •
POSTMARK_VALIDATE_TEMPLATE- Validate template with model data before sending [Optional] - •
POSTMARK_SEND_BATCH_WITH_TEMPLATES- Send batch emails using a template [Required]
Key parameters:
- •
TemplateIdorTemplateAlias: Identifier for the template to use - •
Messages: Array of message objects withFrom,To,TemplateModel - •
TemplateModel: Key-value pairs matching template variables
Pitfalls:
- •Maximum 500 messages per batch call
- •Either
TemplateIdorTemplateAliasis required, not both - •
TemplateModelkeys 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:
- •
POSTMARK_LIST_TEMPLATES- List all templates with IDs and names [Required] - •
POSTMARK_GET_TEMPLATE- Get full template details including HTML/text body [Optional] - •
POSTMARK_EDIT_TEMPLATE- Update template content or settings [Optional] - •
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:
- •
POSTMARK_GET_DELIVERY_STATS- Get bounce counts by type [Required] - •
POSTMARK_GET_OUTBOUND_OVERVIEW- Get sent/opened/clicked/bounced summary [Required] - •
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
- •
messagestreamiddefaults 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:
- •
POSTMARK_GET_BOUNCES- List bounced messages with details [Required] - •
POSTMARK_GET_SPAM_COMPLAINTS- List spam complaint records [Optional] - •
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
countandoffset, not page tokens
5. Configure Server Settings
When to use: User wants to view or modify Postmark server configuration
Tool sequence:
- •
POSTMARK_GET_SERVER- Retrieve current server settings [Required] - •
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
SmtpApiActivatedaffects 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
countfor results per page (varies by endpoint) - •Use
offsetto 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
dataordata.data - •Parse defensively with fallback patterns
- •Template IDs are always numeric integers
Quick Reference
| Task | Tool Slug | Key Params |
|---|---|---|
| Send batch templated emails | POSTMARK_SEND_BATCH_WITH_TEMPLATES | Messages, TemplateId/TemplateAlias |
| List templates | POSTMARK_LIST_TEMPLATES | Count, Offset, TemplateType |
| Get template details | POSTMARK_GET_TEMPLATE | TemplateId |
| Edit template | POSTMARK_EDIT_TEMPLATE | TemplateId, Name, Subject, HtmlBody |
| Validate template | POSTMARK_VALIDATE_TEMPLATE | TemplateId, TemplateModel |
| Delivery stats | POSTMARK_GET_DELIVERY_STATS | (none or date filters) |
| Outbound overview | POSTMARK_GET_OUTBOUND_OVERVIEW | fromdate, todate, tag |
| Get bounces | POSTMARK_GET_BOUNCES | count, offset, type, emailFilter |
| Get spam complaints | POSTMARK_GET_SPAM_COMPLAINTS | count, offset, fromdate, todate |
| Tracked email counts | POSTMARK_GET_TRACKED_EMAIL_COUNTS | fromdate, todate, tag |
| Get server config | POSTMARK_GET_SERVER | (none) |
| Edit server config | POSTMARK_EDIT_SERVER | Name, TrackOpens, TrackLinks |
When to Use
This skill is applicable to execute the workflow or actions described in the overview.
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