Delivery Issues Troubleshooting

Immediate Actions:

1. Check DNS Authentication:
   • Run our DNS Checker
   • Fix any SPF, DKIM, or DMARC issues
   • Wait 24-48 hours for DNS propagation
2. Review Email Content:
   • Avoid spam trigger words in subject lines
   • Use proper HTML formatting
   • Include a clear unsubscribe link
   • Add your physical address
3. Improve Sender Reputation:
   • Start with small sending volumes
   • Maintain low bounce rates (<5%)
   • Keep spam complaints low (<0.1%)

Long-term Improvements:

1. List Management:
   *Smarthost.MX is not intended for bulk emailing large lists
   • Use double opt-in for new subscribers
   • Regularly clean your email list
   • Remove hard bounces immediately
   • Monitor engagement rates
2. Content Best Practices:
   • Maintain consistent sender identity
   • Use clear, descriptive subject lines
   • Balance text and images
   • Test emails before sending
3. Monitoring:
   • Set up DMARC reporting
   • Monitor delivery rates regularly
   • Track spam complaint rates

Hard Bounce Solutions:

1. Invalid Email Addresses:
   • Remove bounced addresses immediately
   • Implement email validation on signup
   • Use double opt-in verification
   • Regular list cleaning
2. Non-existent Domains:
   • Verify domain exists before sending
   • Check for typos in domain names
   • Remove invalid domains from list
3. Blocked Sending:
   • Check if sender domain is blacklisted
   • Contact recipient's IT department
   • Improve sender reputation

Soft Bounce Solutions:

1. Temporary Issues:
   • Wait and retry automatically (we do this)
   • Check if issue persists after 24 hours
   • Convert to hard bounce after 3 days
2. Message Size Issues:
   • Smarthost.MX has a 20MB maximum email size limit
   • Reduce email size if over 20MB (emails will be rejected)
   • For recipients: keep under 10MB for best compatibility
   • Compress or link to large attachments
   • Optimize images and content
3. Full Mailboxes:
   • Retry sending later
   • Contact recipient through alternate means
   • Clean list if issue persists

SPF Record Issues:

1. Missing SPF Record:
   • Add TXT record: v=spf1 include:spf.smarthost.mx ~all
   • Set record name to @ (root domain)
   • Wait for DNS propagation
2. Multiple SPF Records:
   • Combine all SPF mechanisms into one record
   • Remove duplicate SPF records
   • Test with DNS checker tool
3. Missing Smarthost.MX:
   • Add include:spf.smarthost.mx to existing SPF
   • Ensure proper spacing and syntax
   • Keep existing includes if needed

DKIM Record Issues:

1. Missing DKIM Record:
   • Get DKIM record from the DNS Checker tool
   • Add TXT record with provided selector
   • Use exact values provided
2. DKIM Validation Failures:
   • Check for syntax errors in DNS record
   • Verify selector name matches smarthost._domainkey
   • Ensure no extra spaces or characters
3. DMARC Alignment Issues:
   • Ensure From domain matches DKIM domain
   • Check DMARC policy alignment settings
   • Review DMARC reports for specifics

Factors Affecting Speed:

• Recipient Server Load: Busy servers may delay processing
• Sender Reputation: Better reputation = faster delivery
• DNS Resolution: Slow DNS can delay connections
• Content Scanning: Spam filters add processing time
• Volume: Large batches may be throttled

Typical Delivery Times:

Speed Optimization Tips:

1. Improve Authentication:
   • Set up SPF, DKIM, and DMARC
   • Maintain proper DNS records
   • Monitor authentication reports
2. Build Reputation:
   • Start with small volumes
   • Maintain low bounce rates
   • Keep consistent sending patterns
3. Optimize Content:
   • Keep messages under 10MB for best delivery
   • Note: Smarthost.MX maximum is 20MB (larger emails rejected)
   • Use clean, simple HTML
   • Avoid spam trigger content