---
title: X
description: Checking a mail setup usually means a handful of separate tests, one host and one port at a time, and guessing what the results add up to. The new free Mail…
canonical: https://watchfor.io/changelog/2026-10-05-mail-server-checker
---

[All updates](/changelog#2026-10-05-mail-server-checker) ✨ New Oct 5, 2026 · v 9.4.6

# New free tool: Mail Server Checker

Checking a mail setup usually means a handful of separate tests, one host and one port at a time, and guessing what the results add up to. The new free Mail Server Checker takes a domain, finds its inbound MX, SMTP submission, IMAP and POP3 servers, and grades each one A+ to F from three regions, with the exact fix for every problem. It never logs in and never sends a message.

## What it checks

- Encryption: which TLS versions each server accepts (SSL 3.0 to TLS 1.3), weak ciphers, forward secrecy, and whether STARTTLS is offered on ports 25, 587, 143 and 110.

- The certificate: trust chain, name, expiry, key size and signature.

- Login safety: whether a password is accepted before the connection is encrypted.

- Open relay: whether port 25 accepts mail for an outside address. The test stops before any message is sent.

- Inbound mail security: reverse DNS for each MX, MTA-STS, TLS-RPT and DANE, plus a short SPF and DMARC summary that links to the [Email Health](/email-policy-checker) tool.

## How the servers are found

MX records first, then the SRV records mail apps use, then the autoconfig file Thunderbird reads, then common names like imap. and smtp. . Every host says where it came from.

## Three regions

Mail apps' servers are graded from the location nearest to you, and two more regions check reachability, TLS and the certificate. That shows problems a single test misses, such as a server not answering from Asia. Most cloud networks block outbound port 25, so inbound mail is always graded from a location that can reach it, and the report says which one. A server we cannot reach gets no grade.

## Keep watching it

The [IMAP](/docs/monitors/imap#mail-server-grade), [POP3](/docs/monitors/pop3#mail-server-grade) and [SMTP](/docs/monitors/email#smtp) monitors grade the same servers on every check. The checker is free at [/mail-server-checker](/mail-server-checker), and agents can run it as the mail-server-check [live diagnostic](/docs/api/diagnostics).

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Canonical page: https://watchfor.io/changelog/2026-10-05-mail-server-checker · Site guide: https://watchfor.io/llms.txt