| Ecosystem |
| 0 |
| 0 |
| Match Graph | 0 | 0 |
| Pricing | Free | Free |
| Capabilities | 10 decomposed | 9 decomposed |
| Times Matched | 0 | 0 |
Implements a full SMTP server that intercepts outbound emails from applications without requiring code changes. Emails are parsed, stored in-memory or persistent storage, and indexed for retrieval. Uses zero external dependencies for the SMTP protocol implementation, enabling lightweight deployment in development and testing environments.
Unique: Zero-dependency SMTP implementation (no external mail libraries) combined with in-process storage eliminates deployment complexity compared to Docker-based alternatives like MailHog or Mailtrap
vs alternatives: Faster startup and lower resource overhead than containerized email testing tools because it runs as a single binary with no external dependencies
Provides a browser-based dashboard for viewing intercepted emails with full MIME parsing, attachment preview, and raw message inspection. Built with embedded web server that serves HTML/CSS/JavaScript frontend without external web framework dependencies. Supports real-time email list updates and detailed message inspection with syntax highlighting for headers and body content.
Unique: Embedded web server with zero external framework dependencies (no Node.js, no Python Flask required) — entire UI is self-contained in the binary, reducing deployment footprint
vs alternatives: Simpler setup than Mailpit's web UI because MailSandbox is a direct fork optimized for MCP integration without additional service dependencies
Implements Postmark-compatible REST API endpoints that accept email submission requests in Postmark format and route them to the internal SMTP server. Allows applications using Postmark SDK to send emails to MailSandbox without code changes. Supports Postmark request/response schemas including template variables, metadata, and delivery tracking.
Unique: Postmark API compatibility layer allows drop-in replacement for Postmark endpoint without modifying application code — applications using official Postmark SDKs can switch to MailSandbox by changing one configuration value
vs alternatives: More complete Postmark emulation than generic mock servers because it understands Postmark-specific request/response schemas and integrates with the same SMTP backend as direct SMTP testing
Exposes MailSandbox functionality as an MCP (Model Context Protocol) server, allowing AI agents and LLM-powered tools to query, search, and analyze intercepted emails programmatically. Implements MCP resource and tool endpoints for listing emails, retrieving message content, searching by recipient/subject, and analyzing email structure. Enables Claude and other AI models to understand email testing state and assist with debugging email workflows.
Unique: First email testing tool to expose debugging capabilities via MCP protocol, enabling AI agents to understand and reason about email system behavior — bridges gap between email infrastructure and AI-powered development workflows
vs alternatives: Unique positioning as MCP-first email testing tool compared to traditional email testing tools (Mailpit, MailHog) which only expose HTTP APIs unsuitable for LLM integration
Indexes intercepted emails by sender, recipient, subject, timestamp, and custom metadata tags. Provides search API endpoints that support filtering by multiple criteria (e.g., 'emails from user@example.com sent after 2024-01-01'). Uses in-memory indexing for fast queries without external search infrastructure. Supports regex and substring matching on email content.
Unique: Zero-dependency in-memory indexing approach avoids external search infrastructure while supporting complex multi-field queries — trades off scalability for simplicity and fast startup
vs alternatives: Simpler query interface than Mailpit because MailSandbox optimizes for programmatic search via API rather than UI-driven filtering, making it better suited for test automation
Automatically extracts and stores MIME attachments from intercepted emails with support for multiple content types (images, PDFs, text, binary). Provides endpoints to list attachments for a given email, download raw attachment files, and generate previews for supported formats. Uses MIME parsing to identify attachment boundaries and content-type headers without external libraries.
Unique: Zero-dependency MIME parsing for attachment extraction — no external libraries like python-email or node-mailparser required, reducing binary size and startup time
vs alternatives: More efficient attachment handling than Mailpit because MailSandbox uses native MIME parsing optimized for testing workflows rather than general-purpose email processing
Tracks email state through a simulated delivery pipeline (received, processing, delivered, failed) with configurable delays and failure injection. Allows tests to simulate delivery failures, bounces, and delays without modifying application code. Provides API to query delivery status and simulate webhook callbacks for delivery events.
Unique: Integrated delivery simulation without requiring separate mock services — allows testing email error paths in isolation by injecting failures at the MailSandbox level rather than mocking application-level email clients
vs alternatives: More integrated testing experience than mocking email libraries because MailSandbox simulates failures at the protocol level, testing actual application error handling paths
Supports multiple storage backends (in-memory, SQLite, PostgreSQL) for persisting intercepted emails across restarts. Uses pluggable storage interface to abstract backend implementation. Enables long-running test environments and historical email analysis without data loss. Automatically handles schema creation and migrations.
Unique: Pluggable storage backend architecture allows switching between in-memory, SQLite, and PostgreSQL without code changes — enables development with in-memory storage and production-like testing with persistent databases
vs alternatives: More flexible storage options than Mailpit (which uses SQLite only) because MailSandbox supports multiple backends, allowing teams to choose persistence strategy matching their infrastructure
+2 more capabilities
Executes SQL queries against Supabase PostgreSQL instances through the Model Context Protocol, translating natural language or structured query requests into parameterized SQL statements. Uses MCP's tool-calling interface to expose database operations as callable functions with schema validation, enabling LLM agents to perform CRUD operations, joins, and aggregations with automatic connection pooling and credential management through Supabase client SDK.
Unique: Exposes Supabase PostgreSQL as MCP tools with automatic credential injection from Supabase client SDK, eliminating manual connection string management and enabling seamless LLM-to-database queries within Claude or compatible agents
vs alternatives: Tighter integration than generic SQL MCP servers because it leverages Supabase's built-in authentication and connection pooling rather than requiring separate database credential configuration
Exposes Supabase Auth session state and user metadata through MCP tools, allowing agents to inspect current authentication context, retrieve user profiles, and trigger auth-related operations. Integrates with Supabase's JWT-based auth system to validate sessions and access user claims without re-authenticating, using the Supabase client's built-in session management.
Unique: Integrates Supabase's JWT-based auth system directly into MCP tool interface, allowing agents to inspect and act on auth state without managing separate credential stores or re-authentication flows
vs alternatives: More seamless than generic auth MCP servers because it leverages Supabase's built-in session management and avoids redundant credential passing between agent and auth system
Invokes Supabase Edge Functions (serverless TypeScript/JavaScript functions) through MCP tools, passing parameters and receiving results with optional streaming support. Uses Supabase's edge function HTTP API to trigger functions with automatic authentication headers and response parsing, enabling agents to execute custom business logic without embedding it in the agent itself.
Supabase scores higher at 42/100 vs MailSandbox at 26/100.
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Unique: Exposes Supabase Edge Functions as MCP tools with automatic authentication and response parsing, allowing agents to invoke custom serverless logic without managing HTTP clients or credential injection
vs alternatives: More integrated than generic HTTP MCP tools because it handles Supabase-specific authentication, error handling, and response formatting automatically
Subscribes to real-time changes on Supabase tables through MCP's event streaming interface, using Supabase's PostgreSQL LISTEN/NOTIFY mechanism to push INSERT, UPDATE, and DELETE events to agents. Maintains persistent WebSocket connections and filters events by table and row-level policies, enabling agents to react to database changes without polling.
Unique: Bridges Supabase's PostgreSQL LISTEN/NOTIFY real-time system with MCP's tool interface, enabling agents to subscribe to database changes without managing WebSocket connections or event serialization
vs alternatives: More efficient than polling-based approaches because it uses Supabase's native real-time infrastructure rather than repeated database queries
Manages files in Supabase Storage buckets through MCP tools, supporting upload, download, list, and delete operations with automatic authentication and path-based access control. Uses Supabase's S3-compatible storage API with built-in support for public/private buckets and signed URLs for temporary access, enabling agents to handle file I/O without managing cloud storage credentials.
Unique: Exposes Supabase Storage's S3-compatible API as MCP tools with automatic authentication and signed URL generation, eliminating the need for agents to manage cloud storage credentials or generate temporary access tokens
vs alternatives: More integrated than generic S3 MCP tools because it leverages Supabase's built-in bucket policies and authentication rather than requiring separate AWS credentials
Performs semantic similarity searches on vector embeddings stored in Supabase PostgreSQL using pgvector extension, translating natural language queries into embedding vectors and executing cosine/L2 distance searches. Integrates with embedding providers (OpenAI, Cohere) or uses pre-computed embeddings, enabling agents to retrieve semantically similar documents or records without full-text search limitations.
Unique: Integrates pgvector directly into MCP tools with automatic embedding generation and distance calculation, enabling agents to perform semantic search without managing separate vector database infrastructure
vs alternatives: More efficient than external vector databases (Pinecone, Weaviate) for Supabase users because it colocates embeddings with relational data, reducing network latency and simplifying data synchronization
Exposes Supabase database schema information through MCP tools, allowing agents to discover table structures, column types, constraints, and relationships without manual schema documentation. Queries PostgreSQL information_schema and Supabase metadata tables to dynamically generate schema descriptions, enabling agents to construct valid queries and understand data relationships.
Unique: Queries Supabase's PostgreSQL information_schema directly through MCP tools, enabling agents to dynamically discover and adapt to database schemas without pre-configured schema definitions
vs alternatives: More flexible than static schema definitions because it reflects live database state, including recent migrations or schema changes
Enforces Supabase Row-Level Security policies within agent queries, ensuring that agents can only access rows permitted by RLS rules defined in the database. Evaluates policies based on authenticated user context (JWT claims, user ID) and applies WHERE clause filters automatically, preventing unauthorized data access at the database layer rather than application layer.
Unique: Delegates authorization enforcement to PostgreSQL RLS policies rather than implementing authorization in agent code, ensuring that data access rules are centralized and cannot be bypassed by agent logic
vs alternatives: More secure than application-level authorization because RLS is enforced at the database layer, preventing accidental data leaks even if agent code has bugs
+1 more capabilities