Zerosmtp MCP server

by msgwing·io.github.msgwing/zerosmtp·v1.0.2

A free SMTP relay that still takes a username and password, for devices that cannot do OAuth 2.0.

A92/100grade A

What users say

No reviews yet

Safety scan

A92/100

Adoption

Growing

5 stars41 downloads/wk

Reviews

Nobody has reviewed Zerosmtp yet.

If you have run it, two minutes of your experience saves the next person an afternoon.

write = sends, deletes, buys or posts

Read from the package source without running it. The installed server may list more.

check_device_oauth
Look up whether a printer, scanner, NAS or firewall has firmware
check_relay_reachable
Open a real TCP connection and TLS handshake to the relay from THIS
lookup_smtp_error
Identify a Microsoft 365 SMTP AUTH error string and say what it means,
relay_settings
The ZeroSMTP connection values, together with the two limits that decide

scanner v0.1.9 · 2026-09-20 · same rubric, same numbers if you re-run it

no findings

Code scan5 source files scanned25/25
–Live reliabilityno gateway calls yet and no remote to proben/a
–Tool poisoningtools not inspected (local package is not executed); not countedn/a
Auth qualitylocal package, no credentials required12/15
Maintenancelast push 0 days ago15/15
Maintainer identityregistry namespace matches repository owner; GitHub account older than a year8/10

Overall 92/100. Components that don't apply are left out of the denominator. Any critical finding is an F.Rubric Appeal a finding JSON

Runs npx -y zerosmtp-mcp on your machine. Read the scan report first; the gateway never runs local packages.

claude mcp add zerosmtp -- npx -y zerosmtp-mcp

Is Zerosmtp MCP server safe?: Yes, by our scan: it is graded A (92/100). Read the Zerosmtp safety report
How do I install Zerosmtp?: It runs on your machine. Copy the Claude Code, Claude Desktop or Cursor config from the install section.
Does Zerosmtp need an API key?: Not as far as the registry entry and our scan can tell: no credentials are declared or required.
Is Zerosmtp maintained?: The last commit was in the last day (2026-09-20). The latest release is v1.0.2.
What can I use instead of Zerosmtp?: Servers from other publishers that do the same job: Agent Email List — Free SMTP Relay for AI Agents MCP server, Fluxmail MCP server and Outlook MCP server. Compare all Zerosmtp alternatives.

Same job from other publishers: the closest match first, then the best rated.

Agent Email List — Free SMTP Relay for AI Agents
Free transactional email + SMTP relay. Agents self-signup, no API key needed to start.
not reviewed
Growing
B
Fluxmail
Read, search, draft, send, and organize email through Gmail, Outlook, and IMAP/SMTP mailboxes.
not reviewed
Growing
B
Outlook
Outlook integration with OAuth, message search, batch operations, and calendar management
More from mcp-z →
not reviewed
Growing
C
Ecc
Unified MCP server for Email, Calendar & Contacts (Google, M365, Zoho, IMAP/SMTP, DAV).
not reviewed
Growing
B
nintact
Contact forms that actually arrive. No SPF/DKIM, no SMTP. AI sorts them and drafts the reply.
not reviewed
Growing
B