Email Deliverability Checker

Use this interactive checklist to audit your email infrastructure and calculate a deliverability score. Each item represents a critical factor that mail servers evaluate when deciding whether to accept, filter, or reject your emails.

What Is Email Deliverability?

Email deliverability is the measure of how successfully your emails reach the intended recipient's inbox rather than being filtered to spam, quarantined, or rejected entirely. It depends on a combination of technical configuration, sender reputation, and content quality. Poor deliverability means your messages — whether transactional, marketing, or personal — simply never arrive.

Think of it like network connectivity: just as a ping test confirms packets reach their destination, email deliverability confirms your messages reach the inbox. And just as DNS configuration affects how domains resolve, your email DNS records directly impact whether mail servers trust your messages.

The Email Authentication Triad

Three DNS-based authentication mechanisms form the foundation of email deliverability. Without all three properly configured, major providers like Gmail, Outlook, and Yahoo will likely filter your messages:

Verify your records using our DNS Lookup, SPF Record Checker, and DKIM Record Checker.

Pro Tip: Start with a DMARC policy of p=none to monitor authentication failures without affecting delivery. Once you confirm everything passes, gradually tighten to p=quarantine and eventually p=reject. You can check your current DMARC record with a DNS lookup for the TXT record at _dmarc.yourdomain.com.

DNS Requirements for Email

Proper DNS configuration is the technical foundation of email deliverability. Every sending domain needs these records configured correctly:

If you're managing DNS through your router or need to change your DNS settings, make sure these records are properly propagated before sending emails.

Sender Reputation Factors

Mail servers evaluate your sender reputation using multiple signals. A poor reputation leads to emails landing in spam even if your authentication is perfect:

• IP reputation — Whether your sending IP has a history of spam. Check with our IP Blacklist Checker.
• Domain reputation — Your domain's age, history, and sending patterns.
• Bounce rate — High bounce rates (>2%) signal you're sending to invalid addresses.
• Spam complaint rate — If recipients mark your emails as spam, your reputation drops.
• Engagement metrics — Open rates, click rates, and reply rates influence your score at major providers.
• Blacklist status — Appearing on DNSBLs like Spamhaus, Barracuda, or SORBS will severely impact delivery.

Common Deliverability Problems and Solutions

When your emails aren't reaching the inbox, systematically work through these common issues:

Email Deliverability Testing Workflow

Follow this systematic approach to audit and improve your email deliverability:

1. Check DNS records — Use our DNS Lookup to verify SPF, DKIM, DMARC, MX, and PTR records.
2. Test blacklist status — Run your sending IP through the IP Blacklist Checker.
3. Verify ports — Use the Port Checker to confirm ports 25, 587, and 993 are accessible.
4. Send test emails — Send to Gmail, Outlook, and Yahoo accounts and check the raw headers for authentication results.
5. Monitor over time — Track your bounce rate, complaint rate, and inbox placement consistently.

If you need to troubleshoot DNS issues, see our guides on DNS server not responding and changing DNS on your router.

Email Provider Specific Requirements

Major email providers have additional requirements beyond the basics. Meeting these ensures better inbox placement:

• Gmail — Requires SPF or DKIM for all senders. Bulk senders (>5,000/day) must have DMARC with at least p=none, one-click unsubscribe, and spam rate below 0.3%.
• Microsoft/Outlook — Uses SmartScreen filtering and requires proper authentication. Supports DNS over HTTPS for enhanced security.
• Yahoo — Similar requirements to Gmail for bulk senders. Requires DKIM alignment and published DMARC record.
• Apple iCloud — Enforces strict DMARC compliance and rate limits new senders aggressively.

Video: Email Deliverability Best Practices

Related Tools and Guides

• DNS Lookup Tool
• SPF Record Checker
• DKIM Record Checker
• MX Record Checker
• IP Blacklist Checker
• Port Checker
• What Is DNS?
• How to Change DNS on Your Router
• Fix DNS Server Not Responding
• How to Secure Your Home WiFi

Frequently Asked Questions

What is a good email deliverability score?

A deliverability score above 90% is considered excellent and means your emails are reaching the inbox consistently. Scores between 75-90% are good but have room for improvement. Below 75% indicates significant issues with your authentication, reputation, or sending practices that need immediate attention.

Why are my emails going to spam?

Emails land in spam for several reasons: missing or failing SPF/DKIM/DMARC authentication, sending from a blacklisted IP, poor sender reputation, spammy content or subject lines, lack of TLS encryption, or recipients previously marking your emails as spam. Use this checklist to identify which factors are affecting your deliverability.

How long does it take to improve email deliverability?

Technical fixes like adding SPF, DKIM, and DMARC records take effect within hours once DNS propagates. However, rebuilding a damaged sender reputation can take 30-90 days of consistent, clean sending. IP warming for new sending IPs typically requires 2-4 weeks of gradually increasing volume.

Do I need all three: SPF, DKIM, and DMARC?

Yes. While emails can be delivered with only SPF or DKIM, all major providers now recommend (and some require) all three. SPF verifies the sending server, DKIM verifies the message integrity, and DMARC ties them together with a policy. Together they provide the strongest authentication.

What is a PTR record and why does email need one?

A PTR (Pointer) record is a reverse DNS entry that maps an IP address back to a hostname. Many mail servers reject email from IPs without a valid PTR record because legitimate mail servers almost always have reverse DNS configured. Contact your hosting provider or ISP to set up a PTR record for your mail server IP.

How do I check if my IP is blacklisted?

Use our IP Blacklist Checker to query major DNS-based blacklists (DNSBLs). If your IP appears on a blacklist, visit the blacklist provider's website to request removal. Common blacklists include Spamhaus, Barracuda, SORBS, and SpamCop.

What is IP warming?

IP warming is the process of gradually increasing email sending volume from a new IP address over 2-4 weeks. This builds a positive sending reputation with mailbox providers. Start with your most engaged recipients and slowly increase volume by 20-30% daily until you reach your normal sending level.

About Tommy N.

Tommy is the founder of RouterHax and a network engineer with 10+ years of experience in home and enterprise networking. He specializes in router configuration, WiFi optimization, and network security. When not writing guides, he's testing the latest mesh WiFi systems and helping readers troubleshoot their home networks.