DNS Lookup, Email Deliverability Test & Network Tools - SPF, DKIM, DMARC Checker

DNS Lookup Tools, Email Deliverability Checkers & Network Tools

All Free Tools - every tool runs against live DNS in real time.

DNS Lookup Tools

Email Deliverability

Generators

Domain & Network

How mailX Works

Analyze your domain in seconds and get a clear deliverability report with real issues, plain-English explanations, and actionable fixes. No technical expertise required.

1

Enter your domain or IP

Start with your domain or IP address to instantly launch a live DNS lookup and email deliverability full analysis.

2

mailX analyzes your setup

We check DNS records, SPF, DKIM, DMARC, MX configuration, blacklist status, and your full email infrastructure in one flow.

3

You get issues and fixes

Receive a clear report with deliverability issues, DNS errors, and exact steps to fix and improve your inbox placement.

What Does This DNS Lookup & Email Deliverability Test Analyze?

Browse DNS lookup tools, email deliverability checkers, IP lookup tools, and network utilities to analyze your domain and infrastructure.

DNS lookup & records (A, MX, TXT, CNAME, PTR)

Verify your domain configuration and detect DNS issues affecting performance and email routing.

Email authentication (SPF, DKIM, DMARC, BIMI)

Check your authentication setup to prevent spoofing and improve email deliverability.

Deliverability insights & recommendations

Understand why your emails land in spam and how to fix it with clear and actionable insights.

Mail server test

Analyze your mail servers, connectivity, and response time (SMTP, IMAP, MX lookup).

Domain & IP analysis

Perform IP lookup, reverse DNS, and domain checks to validate your infrastructure.

Blacklist check (RBL / DNSBL)

Identify if your domain or IP is listed on spam databases impacting your reputation.

Email Deliverability & DNS Guides

How to Check, Fix and Improve Your Setup

View all articles

Deliverability

Email Deliverability: The Complete Guide to Reaching the Inbox (2026)

Email deliverability refers to the ability of your emails to reach your recipient’s primary inbox rather than being filtered into spam...

Authentication

Why Emails Go to Spam: Causes, Fixes and Deliverability Guide

If your emails are going to spam, the problem is rarely random. Mailbox providers such as Gmail, Outlook...

DNS

DNS: The Guide to Domain Name System, Records and Configuration

DNS (Domain Name System) is the system that translates human-readable domain names into IP addresses...

Go Beyond DNS Lookup and Email Checkers

What makes mailX different from MXToolbox and the rest.

Combined audits

Run SPF + DKIM + DMARC + MX + blacklist in one click and get a single report.

Built for engineers too

Every tool also exposes an MCP server for AI agents and a clean JSON API.

Plain-English explanations

Understand your results without digging through raw DNS records or technical jargon.

Why Are Your Emails Going to Spam

Most deliverability issues come from hidden technical problems affecting your domain reputation and email authentication

Authentication issues (SPF, DKIM, DMARC)

Missing or misconfigured records prevent email providers from verifying your identity.

Reputation & blacklist problems

Poor engagement or blacklist listings quickly damage your sender reputation and inbox placement.

Technical setup & sending behavior

DNS errors, SMTP misconfigurations, or sudden volume changes can trigger spam filters.

Who is mailX for?

mailX is built for teams that rely on email performance and need fast, clear answers when DNS, authentication, or deliverability issues get in the way.

Founders

Launching cold email, newsletters, or transactional flows without burning your domain reputation.

Sales teams

Scaling outbound campaigns while protecting inbox placement, reply rates, and sender trust.

Marketing teams

Improving email performance across campaigns, automations, CRM flows, and lifecycle messaging.

Agencies

Managing multiple domains and clients with faster diagnostics, audits, and clearer reporting.

Developers

Debugging DNS, SMTP, authentication records, and infrastructure issues without jumping between tools.

Built for speed

1 domain to many

Whether you manage a single domain or a large portfolio, we help you identify issues quickly & act with confidence.

DNS, Email Deliverability & Network FAQ

DNS & DOMAIN LOOKUP

What is a DNS lookup?

A DNS lookup queries the Domain Name System to translate a human-readable domain name (like themailx.com) into the underlying records - IP addresses, mail servers, text records - that the rest of the internet uses to route traffic. A DNS lookup retrieves domain records such as A, MX, TXT, CNAME, and PTR to understand how a domain is configured.

What is DNS lookup used for?

DNS lookup is used to troubleshoot domain configuration, email routing, and server connectivity.

How do I check DNS records?

You can use a DNS lookup tool to view and verify your domain’s records and detect configuration issues.

What is DNS propagation?

DNS propagation is the time required for DNS changes to update across global servers.

How long does DNS propagation take?

DNS propagation can take from a few minutes up to 24-48 hours depending on TTL settings.

What is a DNS record?

A DNS record stores information about a domain, such as IP address, mail servers, or verification data.

EMAIL DELIVERABILITY

What is email deliverability?

Email deliverability is the ability of your emails to reach the inbox instead of spam or being blocked.

Why are my emails going to spam?

Emails can go to spam due to missing SPF, DKIM, or DMARC records, blacklist issues, poor sender reputation, or low engagement.

How do I test email deliverability?

Run an email deliverability test that checks DNS records, authentication (SPF, DKIM, DMARC), blacklist status, and SMTP configuration.

What affects email deliverability the most?

The main factors are authentication setup, domain reputation, sending behavior, blacklist status, and email content.

Can DNS issues affect email deliverability?

Yes, incorrect DNS records or missing authentication can cause emails to be rejected or flagged as spam.

SPF, DKIM and DMARC

What is SPF?

SPF (Sender Policy Framework) is a DNS record that defines which servers are allowed to send emails for your domain.

How do I check my SPF record?

Use an SPF checker to validate your SPF record and detect configuration errors.

What is DKIM?

DKIM (DomainKeys Identified Mail) is an email authentication method that adds a cryptographic signature to verify message integrity.

How do I verify DKIM?

You can use a DKIM checker or email header analyzer to confirm that DKIM is correctly configured.

What is DMARC?

DMARC (Domain-based Message Authentication, Reporting and Conformance) is a policy that builds on SPF and DKIM to protect your domain.

What is the difference between SPF, DKIM and DMARC?

SPF verifies sending servers, DKIM verifies message integrity, and DMARC enforces policies and reporting.

How do I create a DMARC record?

You can generate a DMARC record using a DMARC generator and add it to your DNS.

MX Records and SMTP

What is an MX record?

An MX record specifies which mail servers are responsible for receiving emails for a domain.

How do I check MX records?

Use an MX lookup tool to verify your mail server configuration and priorities.

What is SMTP?

SMTP (Simple Mail Transfer Protocol) is used to send emails between servers.

How do I test an SMTP server?

Use an SMTP test tool to check connectivity, response time, and server configuration.

What happens if MX records are misconfigured?

Emails may bounce, fail to deliver, or be delayed.

BLACKLIST and SECURITY

What is a blacklist (DNSBL)?

A blacklist is a database of domains or IP addresses flagged for sending spam.

How do I check if my domain is blacklisted?

Use a blacklist checker to scan your domain or IP against known DNSBL databases.

Why is my domain or IP blacklisted?

Common causes include spam complaints, compromised accounts, or sending to invalid addresses.

How do I remove a blacklist?

Fix the issue causing the listing, then request removal from the blacklist provider.

IP and NETWORK

What is my IP address?

Your IP address is the unique identifier assigned to your device on the internet.

How do I lookup an IP address?

Use an IP lookup tool to find location, ISP, and related domain information.

What is reverse DNS (PTR)?

Reverse DNS maps an IP address back to a domain name and is important for email trust.

What is IP lookup used for?

IP lookup helps identify the location, provider, and reputation of an IP address.

What is WHOIS?

WHOIS is a database that provides information about domain ownership and registration.

Why is IP reputation important?

A poor IP reputation can cause emails to be blocked or sent to spam.

Stop guessing why emails go to spam

Run a complete email deliverability audit and get an actionable report. Takes less than 10 seconds. No signup required.

Run the full deliverability test

Fix Email Deliverability Issues, Check DNS & Analyze Domain