{"passport":{"unfragile":{"@version":"1.0","version":"2026-05","artifact":{"id":"awesome-email-send-mcp","slug":"email-send-mcp","name":"Email Send MCP","type":"mcp","url":"https://github.com/YUHAI0/email-send-mcp","page_url":"https://unfragile.ai/email-send-mcp","categories":["mcp-servers"],"tags":[],"pricing":{"model":"open_source","free":true,"starting_price":null},"status":"active","verified":false},"capabilities":[{"id":"awesome-email-send-mcp__cap_0","uri":"capability://tool.use.integration.smtp.based.email.sending.via.mcp.protocol","name":"smtp-based email sending via mcp protocol","description":"Implements email transmission through standard SMTP protocol exposed as an MCP (Model Context Protocol) server resource. The capability wraps SMTP client initialization, credential management, and message composition into discrete MCP tools that Claude and other MCP-compatible clients can invoke. Handles connection pooling, TLS/SSL encryption negotiation, and SMTP authentication flows transparently, allowing LLM agents to send emails without direct SMTP library dependencies.","intents":["I want my Claude agent to send emails programmatically without managing SMTP connections directly","I need to integrate email notifications into an LLM-powered workflow or automation","I want to expose email sending as a tool that Claude can call during multi-step agent tasks"],"best_for":["LLM application developers building Claude agents with email capabilities","Teams automating notification workflows through AI agents","Developers prototyping email-integrated AI assistants"],"limitations":["Requires valid SMTP credentials (username/password or OAuth tokens) exposed as environment variables or config","No built-in email queuing or retry logic — failures are immediate and not persisted","Limited to SMTP protocol — does not support alternative email delivery services (SendGrid, Mailgun APIs) without custom wrapper","No template rendering engine — email body must be pre-formatted before passing to the tool","Single-threaded SMTP connection — concurrent email sends may queue or timeout under high load"],"requires":["MCP-compatible client (Claude Desktop, or custom MCP host)","Node.js 16+ (typical MCP server runtime)","Valid SMTP server credentials (host, port, username, password)","Network access to SMTP server (port 587 or 465 typically)"],"input_types":["structured JSON with recipient email, subject, body, optional CC/BCC fields","plain text email body","HTML email body"],"output_types":["success/failure status message","SMTP server response code and message","message ID if supported by SMTP server"],"categories":["tool-use-integration","automation-workflow"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"awesome-email-send-mcp__cap_1","uri":"capability://tool.use.integration.multi.recipient.email.composition.with.header.management","name":"multi-recipient email composition with header management","description":"Provides structured email composition supporting multiple recipient types (To, CC, BCC) with full SMTP header control. The capability abstracts SMTP message formatting (RFC 5321/5322 compliance) and allows specification of custom headers, reply-to addresses, and sender information. Handles character encoding (UTF-8) and MIME multipart construction for mixed plain-text and HTML content, delegating low-level formatting to the underlying SMTP library.","intents":["I want to send emails to multiple recipients with CC and BCC fields from my agent","I need to set custom email headers or reply-to addresses for email workflows","I want to compose both plain-text and HTML versions of emails in a single send operation"],"best_for":["Developers building multi-recipient notification systems via agents","Teams needing flexible email composition with custom headers","Applications requiring both HTML and plain-text email variants"],"limitations":["No built-in email template engine — formatting must be done before passing to the tool","Attachment support unknown — may require separate capability or not be supported","No validation of email addresses at composition time — invalid addresses fail at SMTP send","Character encoding limited to UTF-8 — non-UTF-8 content must be pre-encoded","No support for email signing (DKIM, SPF) — relies on SMTP server configuration"],"requires":["MCP-compatible client","SMTP server supporting MIME multipart messages","Valid email addresses for all recipient fields"],"input_types":["structured JSON with to, cc, bcc, subject, body, htmlBody, replyTo fields","plain text subject and body","HTML body content"],"output_types":["SMTP send confirmation","error message if composition or send fails"],"categories":["tool-use-integration","text-generation-language"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"awesome-email-send-mcp__cap_2","uri":"capability://tool.use.integration.environment.based.smtp.credential.management","name":"environment-based smtp credential management","description":"Manages SMTP authentication credentials through environment variables or configuration files, abstracting credential storage from the MCP tool implementation. The capability reads SMTP host, port, username, and password from the runtime environment at server startup and uses them for all subsequent email operations. Supports both plaintext password and OAuth token authentication flows depending on SMTP server capabilities.","intents":["I want to configure SMTP credentials once at startup without hardcoding them in my agent code","I need to switch between different SMTP providers (Gmail, SendGrid, custom servers) by changing environment variables","I want to keep email credentials secure by using environment-based configuration instead of inline secrets"],"best_for":["DevOps teams deploying MCP servers in containerized environments","Developers building multi-tenant email systems with per-tenant SMTP configs","Teams using secrets management systems (AWS Secrets Manager, HashiCorp Vault)"],"limitations":["Credentials must be set before MCP server startup — runtime credential rotation not supported","No built-in credential validation — invalid SMTP credentials only fail when first email is sent","Environment variables exposed in process memory — not suitable for highly sensitive deployments without additional OS-level isolation","No support for credential refresh tokens — OAuth tokens must be manually rotated and redeployed","Single credential set per server instance — multi-account scenarios require multiple server instances"],"requires":["Environment variables set before MCP server process starts","Standard environment variable names (e.g., SMTP_HOST, SMTP_PORT, SMTP_USER, SMTP_PASS)","Valid SMTP server credentials"],"input_types":["environment variable strings"],"output_types":["SMTP connection status at server startup","error if credentials are missing or invalid"],"categories":["tool-use-integration","safety-moderation"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"awesome-email-send-mcp__cap_3","uri":"capability://tool.use.integration.mcp.protocol.server.implementation.for.email.tools","name":"mcp protocol server implementation for email tools","description":"Implements a complete MCP server that exposes email sending capabilities as callable tools through the MCP protocol. The server handles MCP message parsing, tool registration, request routing, and response serialization according to the MCP specification. Allows Claude and other MCP-compatible clients to discover available email tools via the MCP protocol handshake and invoke them with structured arguments.","intents":["I want Claude to discover and call email tools through the standard MCP protocol","I need to expose email capabilities to any MCP-compatible client, not just Claude","I want to build a reusable email service that integrates with the broader MCP ecosystem"],"best_for":["Developers building MCP servers for email automation","Teams integrating email into multi-tool MCP agent systems","Organizations standardizing on MCP for LLM tool integration"],"limitations":["MCP protocol version compatibility — may not work with older or newer MCP client versions without updates","No built-in MCP server discovery — clients must know the server endpoint or be configured manually","Single-threaded request handling — concurrent MCP requests may queue or timeout","No MCP authentication layer — relies on network-level security (firewall, VPN) for access control","Error handling limited to MCP protocol error responses — no custom error codes or detailed diagnostics"],"requires":["MCP-compatible client (Claude Desktop, custom MCP host, etc.)","Node.js 16+ with MCP SDK or equivalent","Network connectivity between client and MCP server"],"input_types":["MCP protocol messages (JSON-RPC format)","tool invocation requests with structured arguments"],"output_types":["MCP protocol responses","tool execution results","error responses in MCP format"],"categories":["tool-use-integration","automation-workflow"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"awesome-email-send-mcp__cap_4","uri":"capability://tool.use.integration.error.handling.and.smtp.failure.reporting","name":"error handling and smtp failure reporting","description":"Captures SMTP protocol errors, connection failures, and authentication issues and surfaces them as structured error responses through the MCP protocol. The capability maps low-level SMTP error codes (e.g., 550 Permanent Failure, 421 Service Unavailable) to human-readable error messages and includes diagnostic information (SMTP server response, connection state) to aid debugging. Errors are returned to the MCP client without retrying or queuing.","intents":["I want my agent to understand why an email send failed and potentially retry or escalate","I need detailed error messages from SMTP failures to debug email delivery issues","I want to handle different types of email failures (auth, network, recipient) differently in my agent logic"],"best_for":["Developers building resilient email agents with fallback logic","Teams debugging email delivery issues in production","Applications requiring detailed error diagnostics for user-facing error messages"],"limitations":["No automatic retry logic — agents must implement their own retry strategies","Error messages depend on SMTP server implementation — different servers may return different error text","No error categorization — agents must parse error messages to determine failure type","Transient vs permanent failures not distinguished — agents cannot automatically decide whether to retry","No error logging or persistence — errors are only visible to the MCP client at invocation time"],"requires":["SMTP server that returns standard error codes","MCP client capable of handling error responses"],"input_types":["SMTP server error responses"],"output_types":["structured error response with error code, message, and diagnostic details","SMTP server response text"],"categories":["tool-use-integration","safety-moderation"],"confidence":0.5,"matches":0,"success_rate":0}],"trust":{"score":25,"verified":false,"data_access_risk":"high","permissions":["MCP-compatible client (Claude Desktop, or custom MCP host)","Node.js 16+ (typical MCP server runtime)","Valid SMTP server credentials (host, port, username, password)","Network access to SMTP server (port 587 or 465 typically)","MCP-compatible client","SMTP server supporting MIME multipart messages","Valid email addresses for all recipient fields","Environment variables set before MCP server process starts","Standard environment variable names (e.g., SMTP_HOST, SMTP_PORT, SMTP_USER, SMTP_PASS)","Valid SMTP server credentials"],"failure_modes":["Requires valid SMTP credentials (username/password or OAuth tokens) exposed as environment variables or config","No built-in email queuing or retry logic — failures are immediate and not persisted","Limited to SMTP protocol — does not support alternative email delivery services (SendGrid, Mailgun APIs) without custom wrapper","No template rendering engine — email body must be pre-formatted before passing to the tool","Single-threaded SMTP connection — concurrent email sends may queue or timeout under high load","No built-in email template engine — formatting must be done before passing to the tool","Attachment support unknown — may require separate capability or not be supported","No validation of email addresses at composition time — invalid addresses fail at SMTP send","Character encoding limited to UTF-8 — non-UTF-8 content must be pre-encoded","No support for email signing (DKIM, SPF) — relies on SMTP server configuration","builder identity is not verified yet","no observed match outcomes yet"],"rank_breakdown":{"adoption":0.05,"quality":0.2,"ecosystem":0.39999999999999997,"match_graph":0.25,"freshness":0.6,"weights":{"adoption":0.25,"quality":0.25,"ecosystem":0.15,"match_graph":0.23,"freshness":0.12}},"observed_outcomes":{"matches":0,"success_rate":0,"avg_confidence":0,"top_intents":[],"last_matched_at":null},"maintenance":{"status":"active","updated_at":"2026-06-17T09:51:03.039Z","last_scraped_at":"2026-05-03T14:00:15.503Z","last_commit":null},"community":{"stars":null,"forks":null,"weekly_downloads":null,"model_downloads":null,"model_likes":null}},"distribution":{"claim_url":"https://unfragile.ai/submit?claim=email-send-mcp","compare_url":"https://unfragile.ai/compare?artifact=email-send-mcp"}},"signature":"M+dm2WpD7F7wgLVDRJwtBWf6PWn20jhuQ/4fKm2Kuh3dZ/0phLMwyFgDlrcsyKrJIlXU/jaAxxO50vk1i2zQCw==","signedAt":"2026-06-21T18:43:17.002Z","signedBy":"unfragile.ai","version":1},"_links":{"self":"https://unfragile.ai/api/v1/passport/email-send-mcp","artifact":"https://unfragile.ai/email-send-mcp","verify":"https://unfragile.ai/api/v1/verify?slug=email-send-mcp","publicKey":"https://unfragile.ai/api/v1/trust-passport-public-key","spec":"https://unfragile.ai/trust","schema":"https://unfragile.ai/schema.json","docs":"https://unfragile.ai/docs"}}