---
title: "Email Checker: Syntax, MX, and Provider Type | SendHQ"
description: Check one address for syntax errors, look up MX records for its domain through two DNS-over-HTTPS resolvers, and see whether the domain is a common free or disposable mailbox provider.
canonical: https://sendhq.cc/tools/email-checker
last-updated: 2026-09-24
---
# Email Checker: Syntax, MX, and Provider Type

Check one address in two steps: local syntax, then public MX evidence for its domain. The result states plainly what a DNS answer can and cannot establish about an address.

## What the check establishes

A well formed address whose domain publishes mail exchangers belongs to a domain that accepts mail somewhere. Free and disposable classifications describe the domain's operator, not the person or the mailbox behind the address.

## What it cannot establish

This tool never contacts a mail server, so it cannot verify that the mailbox exists, that the operator will accept your message, or that anyone still reads it. Establishing existence requires an actual delivery attempt.

## Use it upstream of real verification

Run this check at capture time to reject typos and dead domains cheaply, then let a confirmation message with a scoped link establish genuine mailbox ownership before you rely on the address.

## Questions about this tool

**Does valid syntax with MX answers mean the email is deliverable?**

No. It means the address is well formed and the domain publishes mail exchangers. Delivery depends on the mailbox, the operator's policy, your sending reputation, and content.

**Can this tool verify that an email address exists?**

No. Verifying existence requires a delivery attempt to that mailbox, which this tool never makes. Provider classifications are domain-level observations.

**Why is the provider list limited?**

A static list covers well known operators only. New disposable domains appear constantly, so an unlisted domain is unknown rather than safe.