Email Deliverability Solution

Fix Email Deliverability Issues

Email delivery problems are often caused by DNS, authentication, reputation or mail server configuration issues. Diagnose SPF, DKIM, DMARC, MX, reverse DNS and blacklist problems before they affect your sending domain.

Start with our SPF, DKIM and DMARC checkers, or read the SPF guide and DMARC enforcement guide.

Run Email Health Check Get Help

Technical DNS and mail-server configuration help for domains, hosting email and VPS mail setups.

SPF • DKIM • DMARC • MX • Reverse DNS • Blacklist

When you need this

Use this page if your emails are delayed, rejected, unauthenticated or landing in spam.

  • Emails go to spam
  • SPF, DKIM or DMARC fail
  • Domain or IP appears on a blacklist
  • Mail server IP has missing reverse DNS
  • Google or Microsoft rejects messages
  • Email provider or hosting was recently changed

Recommended diagnostic path

Start broad, then narrow down the exact email delivery issue.

  1. Run a full email health check

    Start with the Domain Health Checker to review DNS, email authentication, SSL, reputation and website signals.

    Run Domain Health Check →

  2. Validate authentication

    Check SPF, DKIM and DMARC records for missing, weak or misconfigured policies.

    SPF Checker → DKIM Checker → DMARC Checker →

  3. Review mail routing and server identity

    Check MX records and reverse DNS to confirm mail routing and sending IP identity.

    MX Lookup → Reverse DNS Checker →

  4. Check reputation signals

    Review blacklist status and provider results before requesting delisting.

    Blacklist Checker →

Run focused checks for each layer of mail authentication and reputation.

SPF Checker

Validate authorized senders.

Run check →

DKIM Checker

Verify selector and public key.

Run check →

DMARC Checker

Review policy and alignment.

Run check →

MX Lookup

Check incoming mail routing.

Run check →

Blacklist Checker

IP and domain reputation.

Run check →

Reverse DNS

PTR and FCrDNS validation.

Run check → Recommended start

Domain Health

Full diagnostic report.

Run check →

Need help after running diagnostics?

Run the checks above first. If the report shows email authentication, routing, reverse DNS or reputation issues, we can review SPF, DKIM, DMARC, MX, PTR and blacklist signals and route the request if support is needed.

  • SPF, DKIM and DMARC configuration
  • MX and mail routing review
  • Reverse DNS / PTR setup
  • Blacklist and reputation troubleshooting
  • Hosting, VPS and mail server support
Run Email Health Check Get Help

Common email deliverability problems

SPF record problems

Broken SPF can fail authentication and hurt sender trust with major inbox providers.

Check SPF →

DKIM not configured

Missing DKIM means receivers cannot verify message integrity or sender identity.

Check DKIM →

DMARC policy too weak

Weak DMARC leaves spoofing risk and limits protection for your domain.

Check DMARC →

MX or mail routing issues

Incorrect MX records can block inbound mail or send it to the wrong host.

Check MX →

Reverse DNS mismatch

Missing PTR records on sending IPs can trigger spam filters and reduce trust.

Check reverse DNS →

Blacklist listings

A listed IP or domain can cause bounces or spam-folder delivery until resolved.

Check blacklist →

Technical review areas

  • Authentication SPF, DKIM, DMARC
  • Mail routing MX, provider, host resolution
  • Reputation & identity Blacklist, rDNS, PTR

Choose how you want to fix it

DIY diagnosis

Use the free tools to identify issues and copy recommended DNS records.

Run Email Health Check

Assisted configuration

Get help reviewing DNS, mail server settings, reverse DNS and reputation issues.

Get Help

How the fix process works

From diagnosis to DNS changes and verification.

  1. Diagnose

    Run the diagnostic tools to find SPF, DKIM, DMARC, MX, reverse DNS or blacklist issues.

  2. Apply DNS and server changes

    Update DNS records, mail server settings or ask your provider to apply the recommended fixes.

  3. Recheck after propagation

    Verify results again once DNS and server changes have had time to propagate.

DNS changes may take time to propagate depending on TTL and provider settings.

Example email deliverability action plan

A typical fix plan may include several DNS and mail server updates.

Priority 1

Fix SPF syntax

Recommended fix: Publish a single valid SPF record with authorized senders.

Check SPF →
Priority 2

Enable DKIM signing

Recommended fix: Add the DKIM public key record and enable signing in your mail system.

Check DKIM →
Priority 3

Review DMARC policy

Recommended fix: Monitor with p=none first, then tighten to quarantine or reject once SPF and DKIM are stable.

Check DMARC →
Priority 4

Configure reverse DNS

Recommended fix: Ask your hosting provider to set PTR records for sending IPs.

Check reverse DNS →
Priority 5

Review blacklist status

Recommended fix: Fix the root cause before requesting delisting.

Check blacklist →

These checks improve technical configuration, but they do not guarantee inbox placement.

Start with free email diagnostics

Run SPF, DKIM, DMARC, MX, reverse DNS and blacklist checks to find the issue before requesting hands-on support.

Run Email Health Check Get Help

Frequently asked questions

Missing or incorrect SPF, DKIM, DMARC, MX, reverse DNS issues, blacklist listings and poor sending reputation are common causes.
No. SPF, DKIM and DMARC improve authentication, but inbox placement also depends on reputation, content and receiver filtering.
SPF is a DNS record that lists which servers may send email for your domain.
DKIM adds a cryptographic signature so receivers can verify a message was not altered in transit.
DMARC tells receivers how to handle messages that fail SPF or DKIM and can send reports to domain owners.
Many mail systems check PTR records on sending IPs. Missing or mismatched reverse DNS can reduce mail server trust.
Yes. we can help with DNS, mail server setup, email authentication, reverse DNS and hosting-related email configuration.