Email Inbox API + Sending by Sendmux
REMOTE · MCP.SENDMUX.AI · 2 COMPONENTS · SCANNED SEP 20
AI email inbox and sending tools with attachments, search, live events, and webhooks.
Available components
How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. How we score → Why this is hard to score →
Endpoint Security95
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- The endpoint enforces authorisation, advertised via RFC 9728 protected-resource metadata. View diagnostics → Pass
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC is configured correctly; the domain's records validate against the full chain to the root. View diagnostics → Pass
- The authorisation server supports Client ID Metadata Documents, the current MCP client-registration mechanism. View diagnostics → Pass
Transport & Reachability0
- Transport blocked by authentication: the endpoint requires auth we don't have to verify streamable-http. See how to fix → View diagnostics → Unverified
Schema Quality & AI Usability0
- Schema blocked by authentication: the endpoint requires auth we don't have to read it. See how to fix → Unverified
Stability & Change Management0
- Stability not yet verified: not enough scan history yet (needs a 30-day window).Unverified
Tool Coverage0
- Tool coverage blocked by authentication: the endpoint requires auth we don't have to read its tools.Unverified
Tool Safety0
- Tool safety blocked by authentication: the endpoint requires auth we don't have to read its tools.Unverified
Capabilities0
- Capabilities blocked by authentication: the endpoint requires auth we don't have to read them. See how to fix → Unverified
Unverified: 6 categories
Categories scored 0 because we could not verify them: authentication we do not have, an unreachable endpoint, or not enough scan history. We only credit what we can confirm. Claim this server and supply a read-only token to verify it and lift the score.
How do I install the Email Inbox API + Sending by Sendmux MCP server?
Email Inbox API + Sending by Sendmux is a hosted endpoint at https://mcp.sendmux.ai/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.
remote · mcp.sendmux.ai
claude mcp add --transport http sendmux-sendmux-mcp 'https://mcp.sendmux.ai/mcp'
{
"mcpServers": {
"sendmux-sendmux-mcp": {
"url": "https://mcp.sendmux.ai/mcp"
}
}
} {
"servers": {
"sendmux-sendmux-mcp": {
"type": "http",
"url": "https://mcp.sendmux.ai/mcp"
}
}
} [mcp_servers.sendmux-sendmux-mcp] url = "https://mcp.sendmux.ai/mcp"
{
"$schema": "https://opencode.ai/config.json",
"mcp": {
"sendmux-sendmux-mcp": {
"type": "remote",
"url": "https://mcp.sendmux.ai/mcp",
"enabled": true
}
}
} openclaw mcp add sendmux-sendmux-mcp --url 'https://mcp.sendmux.ai/mcp' --transport streamable-http
mcp_servers:
sendmux-sendmux-mcp:
url: "https://mcp.sendmux.ai/mcp" {
"McpServers": {
"sendmux-sendmux-mcp": {
"Transport": "http",
"Url": "https://mcp.sendmux.ai/mcp"
}
}
} assistant mcp add sendmux-sendmux-mcp -t streamable-http -u 'https://mcp.sendmux.ai/mcp'
{
"mcpServers": {
"sendmux-sendmux-mcp": {
"type": "http",
"url": "https://mcp.sendmux.ai/mcp"
}
}
} The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 17 Sept 26 +2
- Authorization: partial → pass ▲ security
- 26 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 11 Aug 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 31 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 30 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 27 Jul 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
- 26 Jul 26 0
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 20 Sept 2026 · Probed https://mcp.sendmux.ai/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=mcp.sendmux.ai | CN=YR2,O=Let's Encrypt,C=US | 18 Aug 2026 | 16 Nov 2026 | RSA 2048 | SHA256-RSA | 65f3d76e2dc21c79320acb40ecd9d42817f |
| SANs: a2a.sendmux.ai, mcp.sendmux.ai | ||||||
| CN=YR2,O=Let's Encrypt,C=US (CA) | CN=Root YR,O=ISRG,C=US | 3 Sept 2025 | 2 Sept 2028 | RSA 2048 | SHA256-RSA | 4ebd24947e24d394802d84a52fd5b319 |
| CN=Root YR,O=ISRG,C=US (CA) | CN=ISRG Root X1,O=Internet Security Research Group,C=US | 13 May 2026 | 2 Sept 2032 | RSA 4096 | SHA256-RSA | f24b6d17f9d9ad7cb1c9fea78782699f |
Background: What to check on a remote MCP endpoint →
DNSSEC secure
Validation of mcp.sendmux.ai. — Secure
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| ai. | present | 3799 | 8 | Verified |
| sendmux.ai. | present | 2371 | 13 | Verified |
| mcp.sendmux.ai. | Verified address RRset verified with the apex keys |
Authentication Enforced and verified
The endpoint asked for a token and published valid RFC 9728 metadata describing how to get one.
| Result | Enforced and verified |
|---|---|
| Enforced | On connection |
| HTTP status | 401 |
WWW-Authenticate challenge Bearer resource_metadata="https://mcp.sendmux.ai/.well-known/oauth-protected-resource/mcp", scope="analytics.read billing.read domain.create domain.read domain.verify email.send logs.read mailbox.admin.create mailbox.admin.manage mailbox.admin.read mailbox.read mailbox.settings.update webhook.create webhook.manage webhook.read"
Bearer resource_metadata="https://mcp.sendmux.ai/.well-known/oauth-protected-resource/mcp", scope="analytics.read billing.read domain.create domain.read domain.verify email.send logs.read mailbox.admin.create mailbox.admin.manage mailbox.admin.read mailbox.read mailbox.settings.update webhook.create webhook.manage webhook.read"| Header | Value |
|---|---|
| www-authenticate | Bearer resource_metadata="https://mcp.sendmux.ai/.well-known/oauth-protected-resource/mcp", scope="analytics.read billing.read domain.create domain.read domain.verify email.send logs.read mailbox.admin.create mailbox.admin.manage mailbox.admin.read mailbox.read mailbox.settings.update webhook.create webhook.manage webhook.read" |
Protected resource metadata
| Document | https://mcp.sendmux.ai/.well-known/oauth-protected-resource/mcp |
|---|---|
| Retrieved | Yes |
| Resource | https://mcp.sendmux.ai/mcp |
| Authorisation server | https://app.sendmux.ai |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://mcp.sendmux.ai/mcp | Auth required | 401 | |
| http (plaintext) | http://mcp.sendmux.ai/mcp | HTTPS enforced | 301 | https://mcp.sendmux.ai/mcp |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
No tool schema has been captured from this endpoint yet.
What is the Email Inbox API + Sending by Sendmux MCP server?
Email Inbox API + Sending by Sendmux is an MCP server listed in the public MCP registry as io.github.Sendmux/sendmux-mcp. AI email inbox and sending tools with attachments, search, live events, and webhooks. This page covers its hosted endpoint (https://mcp.sendmux.ai/mcp).
Is the Email Inbox API + Sending by Sendmux MCP server safe to use?
Email Inbox API + Sending by Sendmux scores 38 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.
Does the Email Inbox API + Sending by Sendmux MCP server require authentication?
Yes. Email Inbox API + Sending by Sendmux asked us for credentials when we connected, so you will need to authorise it in your MCP client before it can do anything.
Is the Email Inbox API + Sending by Sendmux MCP server still maintained?
Email Inbox API + Sending by Sendmux is still listed as active in the MCP registry. We last reached this channel on 20 September 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.