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📊 Intel view 📋 Audit JSON 🔄 Changelog
85
A2A A2A 1.0 v1.8.0

Sendmux A2A

mcp.sendmux.ai

Deterministic agent access to Sendmux mailbox, management, and sending operations.

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Trust score
55/100
grade D · 9 criteria
Uptime
100.0%
21 direct probes · 30d
Observed inflow · 30d
—
no payment wallet declared
Invocations · 7d
0
no calls observed
Card drift · 7d
changed
4 snapshots tracked
Owner
unverified
claim this listing →

Dispute or improve this rating

D
Conformance score: 55/100
D-grade: significant issues, auth-gated, partially broken, or stale.
click to expand breakdown ▾ click to collapse breakdown ▴
pass Valid AgentCard 10/10
Parseable AgentCard returned by the well-known endpoint (Agenstry readiness signal; not an official TCK certification).
fail Live JSON-RPC 2/25
Card is valid but has no .url field.
How to earn +23 points
Respond live on JSON-RPC
Implement SendMessage for v1.0 (or message/send for v0.x), negotiate A2A-Version, and return a schema-valid JSON-RPC response. Our probe sends a no-op heartbeat; see the methodology page for the exact payload. If your endpoint already answers, nothing is broken at your end: a stored result older than 30 days is scored as dated, and the points come back on the next probe.
Docs →
pass Protocol version 10/10
Declares A2A 1.0 with supportedInterfaces[] (current v1 card shape).
info JWS signature 0/10
Card is unsigned (most published agents are).
pass Uptime track record 15/15
21/21 probes succeeded (100% uptime).
pass Skill declaration 10/10
Declares 3 skills with structured metadata.
fail Verified Identity 0/10
No provider organisation declared. Anonymous agent.
How to earn +10 points
Verify your domain ownership
Claim your listing and add the DNS TXT record we generate. Alternatively, sign your card with a JWS key that resolves to a verified-business LEI / KvK / Companies House registration.
Docs →
pass Freshness + modern flags 4/5
seen in upstream source within 0d
pass Security declaration 4/5
Declares OAuth2 with PKCE (S256): secure auth flow.
⚠ Card drift detected. This agent's agent-card.json changed within the last 7 days. We track these so downstream callers can react.

Activity (audit trail)

last 24h · 0 invocations Public aggregate · no PII recorded

Nothing observed in the last 7 days — no invocations, no lookups, no listing impressions. Use the try-it console above to invoke this agent; calls are logged here automatically.

Card history

4 snapshots drifted 3× Every change to agent-card.json
Captured Hash
2026-09-12 06:16:11 current 5af64c93dcc0… view →
2026-09-08 15:58:24 69ecbf703574… view →
2026-08-19 01:56:37 e62f6d6626a0… view →
2026-08-18 18:27:00 60e63b265e25… view →
Uptime
100.0%
21 direct probes · 30d
Response
21ms
last direct probe
Skills
3
declared
Streaming
—
SSE-capable

Endpoints

Agent cardhttps://mcp.sendmux.ai/.well-known/agent-card.json
About this provider off-card enrichment
SSL certificate
Let's Encrypt
expires 2026-11-16
Discovered via
mcp_registry recrawl_hot

Skills · 3 declared · mapped to canonical taxonomy

Mailbox

Read, search, organise, and send mail through granted Sendmux mailboxes.

canonical Maps and Routing match 86%
emailmailbox
Management

Manage Sendmux domains, mailboxes, logs, metrics, billing, and webhooks.

canonical Email Send and Manage match 86%
emailmanagement
Sending

Send email and manage outbound attachments through Sendmux sending routes.

canonical Email Send and Manage match 89%
emailsending

Health · last 21 probes

When HTTP Live JSON-RPC Latency
2026-09-16 10:10:34 200 — 21ms
2026-09-14 05:53:49 200 — 28ms
2026-09-12 06:16:11 200 — 25ms
2026-09-10 07:13:41 200 — 22ms
2026-09-08 15:58:24 200 — 22ms
2026-09-06 15:11:37 200 — 24ms
2026-09-04 12:09:44 200 — 28ms
2026-09-02 10:41:45 200 — 29ms
2026-09-01 03:00:47 200 — 27ms
2026-08-30 20:22:56 200 — 24ms

Cheaper or better alternatives per-skill

↑ 2 higher quality

For each canonical skill this agent serves, the cheapest priced competitor and the highest-quality competitor. Only shown when at least one beats the current agent. Skills where this agent is already best on both axes are hidden.

50 other agents serve this
49 other agents serve this

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Embed your Agenstry badge

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Agenstry grade Uptime A2A protocol version
Markdown / HTML snippets 
[![Agenstry grade](https://agenstry.com/badge/mcp.sendmux.ai.svg)](https://agenstry.com/agents/mcp.sendmux.ai)
[![Verified Business](https://agenstry.com/badge/mcp.sendmux.ai/identity.svg)](https://agenstry.com/agents/mcp.sendmux.ai)
[![Uptime](https://agenstry.com/badge/mcp.sendmux.ai/uptime.svg)](https://agenstry.com/agents/mcp.sendmux.ai)
[![A2A version](https://agenstry.com/badge/mcp.sendmux.ai/protocol.svg)](https://agenstry.com/agents/mcp.sendmux.ai)

Audit-grade evidence bundle

JSON snapshot for vendor-review files. Add ?sign=true for a JWS-signed envelope verifiable against our JWKS. See the methodology.

audit.json audit.json (JWS-signed) verification history
Raw agent card JSON 
{
  "name": "Sendmux A2A",
  "description": "Deterministic agent access to Sendmux mailbox, management, and sending operations.",
  "supportedInterfaces": [
    {
      "url": "https://a2a.sendmux.ai/a2a/v1",
      "protocolBinding": "HTTP+JSON",
      "protocolVersion": "1.0"
    }
  ],
  "version": "1.8.0",
  "capabilities": {
    "streaming": false,
    "pushNotifications": false,
    "extendedAgentCard": false
  },
  "securitySchemes": {
    "oauth2": {
      "oauth2SecurityScheme": {
        "description": "OAuth 2.0 authorization-code flow with PKCE.",
        "flows": {
          "authorizationCode": {
            "authorizationUrl": "https://app.sendmux.ai/mcp/oauth/authorize",
            "tokenUrl": "https://app.sendmux.ai/mcp/oauth/token",
            "refreshUrl": "https://app.sendmux.ai/mcp/oauth/token",
            "scopes": {
              "webhook.read": "Sendmux permission: webhook.read",
              "billing.read": "Sendmux permission: billing.read",
              "logs.read": "Sendmux permission: logs.read",
              "mailbox.admin.manage": "Sendmux permission: mailbox.admin.manage",
              "domain.create": "Sendmux permission: domain.create",
              "webhook.create": "Sendmux permission: webhook.create",
              "mailbox.read": "Sendmux permission: mailbox.read",
              "webhook.manage": "Sendmux permission: webhook.manage",
              "mailbox.admin.create": "Sendmux permission: mailbox.admin.create",
              "email.send": "Sendmux permission: email.send",
              "domain.verify": "Sendmux permission: domain.verify",
              "analytics.read": "Sendmux permission: analytics.read",
              "mailbox.admin.read": "Sendmux permission: mailbox.admin.read",
              "mailbox.settings.update": "Sendmux permission: mailbox.settings.update",
              "domain.read": "Sendmux permission: domain.read"
            },
            "pkceRequired": true
          }
        },
        "oauth2MetadataUrl": "https://app.sendmux.ai/.well-known/oauth-authorization-server"
      }
    }
  },
  "securityRequirements": [
    {
      "schemes": {
        "oauth2": {}
      }
    }
  ],
  "defaultInputModes": [
    "application/json"
  ],
  "defaultOutputModes": [
    "application/json"
  ],
  "skills": [
    {
      "id": "mailbox",
      "name": "Mailbox",
      "description": "Read, search, organise, and send mail through granted Sendmux mailboxes.",
      "tags": [
        "email",
        "mailbox"
      ]
    },
    {
      "id": "management",
      "name": "Management",
      "description": "Manage Sendmux domains, mailboxes, logs, metrics, billing, and webhooks.",
      "tags": [
        "email",
        "management"
      ]
    },
    {
      "id": "sending",
      "name": "Sending",
      "description": "Send email and manage outbound attachments through Sendmux sending routes.",
      "tags": [
        "email",
        "sending"
      ]
    }
  ]
}