Email Deliverability Best Practices

Email Deliverability Best Practices

Email deliverability best practices include setting up SPF, DKIM, and DMARC authentication, maintaining clean email lists, sending relevant content, using double opt-in, monitoring engagement metrics, warming up new IPs gradually, avoiding spam triggers, and regularly monitoring deliverability metrics.

Quick Answer

Email deliverability best practices include setting up SPF, DKIM, and DMARC authentication, maintaining clean email lists, sending relevant content, using double opt-in, monitoring engagement metrics, warming up new IPs gradually, avoiding spam triggers, and regularly monitoring deliverability metrics.

Understanding Email Deliverability Best Practices

Following email deliverability best practices helps ensure your emails reach the inbox consistently. These practices are based on industry standards, receiving server requirements, and proven strategies that improve deliverability over time. Implementing these practices helps build and maintain good sender reputation.

Authentication Best Practices

Set Up All Three Authentication Records

SPF (Sender Policy Framework)

• Add all email service providers to your SPF record
• Use include: statements for each provider
• End with ~all (soft fail) or -all (hard fail) after monitoring
• Only have one SPF record per domain

DKIM (DomainKeys Identified Mail)

• Set up DKIM for all sending domains
• Use the selectors provided by your email service provider
• Verify DKIM records are correctly configured
• Monitor DKIM signing rates

DMARC (Domain-based Message Authentication)

• Start with p=none to monitor without affecting delivery
• Set up aggregate reporting (rua=) to receive DMARC reports
• Gradually move to stricter policies (p=quarantine then p=reject)
• Review DMARC reports regularly to identify issues

Why it matters: Authentication is the foundation of deliverability. Without proper authentication, receiving servers can't verify your emails are legitimate, leading to filtering or rejection.

List Management Best Practices

Use Double Opt-In

What it is: Requiring subscribers to confirm their email address after signing up

Benefits:

• Reduces invalid addresses
• Improves list quality
• Reduces spam complaints
• Builds engaged subscriber base

How to implement:

1. Send confirmation email after signup
2. Require click on confirmation link
3. Only add to list after confirmation
4. Send welcome email after confirmation

Maintain Clean Lists

Remove hard bounces immediately

• Hard bounces are permanent failures
• Remove addresses that hard bounce
• Don't retry hard bounces

Handle soft bounces

• Monitor soft bounces (temporary failures)
• Remove addresses that soft bounce repeatedly (3+ times)
• Retry soft bounces once or twice

Remove inactive subscribers

• Identify subscribers who haven't engaged in 6-12 months
• Send re-engagement campaign
• Remove those who don't re-engage

Regular list cleaning

• Clean lists quarterly or monthly
• Remove invalid addresses, spam traps, and inactive subscribers
• Maintain list hygiene standards

Honor Unsubscribes Immediately

Process unsubscribes within 24 hours

• Remove from all lists immediately
• Never email unsubscribed addresses
• Make unsubscribing easy and clear

Include unsubscribe links

• Required by law in many regions (CAN-SPAM, GDPR)
• Make unsubscribe link prominent and easy to find
• Use one-click unsubscribe when possible

Content Best Practices

Write Relevant, Valuable Content

Match recipient expectations

• Deliver on what you promised at signup
• Send content relevant to subscriber interests
• Segment lists for better targeting

Provide value

• Educational content, tips, insights
• Exclusive offers or information
• Content that helps recipients

Avoid misleading content

• Honest subject lines that match content
• No clickbait or deceptive claims
• Clear, transparent messaging

Avoid Spam Triggers

Avoid spam trigger words

• Words like "free," "guarantee," "act now," "limited time"
• Excessive punctuation (!!!, ???)
• All caps in subject lines or content

Use natural language

• Conversational, brand-appropriate tone
• Professional but not overly formal
• Clear and concise

Test spam scores

• Use spam checker tools before sending
• Aim for low spam scores
• Adjust content if scores are high

Proper Email Formatting

Balance images and text

• Don't send image-only emails
• Maintain at least 60% text content
• Use alt text for all images

Clean HTML structure

• Well-formatted, valid HTML
• Test in multiple email clients
• Responsive design for mobile

Include plain text version

• Always include both HTML and plain text
• Some filters prefer plain text
• Improves accessibility

Proper link formatting

• Use reputable link shorteners if needed
• Avoid suspicious or blacklisted domains
• Make links clear and descriptive

Sending Best Practices

Warm Up New IP Addresses

Start with small volumes

• Begin with 50-100 emails per day
• Gradually increase over 2-4 weeks
• Monitor metrics closely during warm-up

Maintain consistency

• Send regularly during warm-up
• Don't skip days or send sporadically
• Build sending pattern gradually

Monitor closely

• Watch bounce rates, complaints, engagement
• Adjust if metrics are poor
• Slow down if issues arise

Maintain Consistent Sending

Regular sending schedule

• Don't disappear for months then send suddenly
• Maintain consistent frequency
• Set expectations with subscribers

Avoid volume spikes

• Sudden increases can trigger filters
• Gradual increases are safer
• Plan for volume growth

Appropriate frequency

• Not too frequent (hurts engagement)
• Not too infrequent (reduces recognition)
• Find balance for your audience

Segment Your Lists

By engagement level

• Active subscribers (recent opens/clicks)
• Inactive subscribers (no engagement)
• New subscribers (recent signups)

By interests or preferences

• Content preferences
• Product interests
• Geographic location

By behavior

• Purchase history
• Website activity
• Email interaction patterns

Benefits: Segmentation improves relevance, engagement, and deliverability.

Engagement Best Practices

Encourage Opens

Write compelling subject lines

• Clear, honest, relevant
• Avoid spam triggers
• Test different approaches

Send at optimal times

• Test different send times
• Consider time zones
• Find when audience is most engaged

Use preheader text

• Preview text that appears after subject line
• Complements subject line
• Encourages opens

Encourage Clicks

Clear calls-to-action

• Obvious, prominent CTAs
• Action-oriented language
• Easy to click (mobile-friendly)

Relevant content

• Content that matches interests
• Valuable information or offers
• Clear value proposition

Personalization

• Use recipient names
• Relevant content based on preferences
• Personalized recommendations

Encourage Replies

Ask questions

• Invite feedback
• Encourage responses
• Two-way communication

Reply-to address

• Use real email address (not no-reply)
• Monitor and respond to replies
• Build relationships

Why it matters: Two-way engagement is highly valued by receiving servers and improves deliverability.

Monitoring Best Practices

Track Key Metrics

Bounce rates

• Target: Under 2% overall
• Hard bounces: 0%
• Monitor trends over time

Open rates

• Varies by industry
• Track trends, not just absolute numbers
• Compare to industry benchmarks

Click rates

• Varies by industry
• Track engagement trends
• Identify what content performs best

Spam complaint rates

• Target: Under 0.1% (1 per 1,000)
• Monitor closely—complaints hurt reputation
• Address issues immediately if rates spike

Unsubscribe rates

• Target: Under 0.5% per campaign
• Monitor trends
• High rates may indicate content or frequency issues

Review DMARC Reports

Regular review

• Check aggregate reports weekly or monthly
• Look for authentication failures
• Identify spoofing or unauthorized use

Take action

• Fix authentication issues immediately
• Investigate spoofing attempts
• Adjust policies based on data

Use Deliverability Tools

Inbox placement testing

• Test emails to major providers
• Identify deliverability issues
• Monitor inbox vs. spam placement

Sender reputation monitoring

• Track IP and domain reputation scores
• Monitor changes over time
• Address issues if scores drop

Email service provider analytics

• Use built-in analytics
• Track metrics over time
• Identify trends and issues

Compliance Best Practices

Follow Legal Requirements

CAN-SPAM Act (US)

• Include physical mailing address
• Clear unsubscribe mechanism
• Honor unsubscribes promptly
• Don't use deceptive headers

GDPR (EU)

• Obtain explicit consent
• Allow data access and deletion
• Clear privacy policies
• Honor opt-out requests

CASL (Canada)

• Obtain express consent
• Include identification information
• Honor unsubscribe requests

Permission-Based Lists

Only email opt-ins

• Never buy or rent lists
• Only email people who explicitly opted in
• Double opt-in preferred

Clear consent

• Make signup process clear
• Explain what subscribers will receive
• Set expectations upfront

Common Questions

Q: Do I need to follow all best practices, or can I pick and choose?

A: While you don't need to implement everything at once, following comprehensive best practices provides the best results. Start with authentication (essential), then add list management, content quality, and monitoring practices over time.

Q: How quickly will I see results from following best practices?

A: Some practices have immediate impact (authentication fixes), while others take time (reputation building). Authentication improvements can show results within hours, but building reputation takes weeks or months of consistent good practices.

Q: Is double opt-in really necessary?

A: While not always required by law, double opt-in is a best practice that significantly improves list quality, reduces bounces and complaints, and improves deliverability. It's highly recommended.

Q: How often should I clean my email list?

A: Regular cleaning is essential—quarterly or monthly is recommended. Remove hard bounces immediately, handle soft bounces promptly, and remove inactive subscribers regularly.

Q: What's the best sending frequency?

A: There's no one-size-fits-all answer. Test different frequencies with your audience. Too frequent hurts engagement, while too infrequent reduces recognition. Find the balance that works for your subscribers.

Q: Do I need to warm up a new IP even if I follow all best practices?

A: Yes, even with excellent practices, new IP addresses need warm-up. Receiving servers don't have history for new IPs, so gradual volume increases help build reputation safely.

Q: How do I know if I'm following best practices correctly?

A: Monitor your metrics—good deliverability metrics (low bounces, good engagement, low complaints) indicate you're following best practices. Use deliverability tools to test inbox placement.

Q: Can I skip some best practices if my deliverability is already good?

A: While you might have good deliverability now, skipping best practices can lead to problems later. Best practices help maintain good deliverability over time and prevent issues.

Q: What's the most important best practice?

A: Authentication is the foundation—without SPF, DKIM, and DMARC, other practices matter less. However, all practices work together. Focus on authentication first, then add other practices.

Q: How do I implement best practices if I'm already sending emails?

A: Start with authentication if not already set up. Then gradually implement other practices: clean your list, improve content, segment lists, monitor metrics. You don't need to do everything at once, but consistent improvement helps.

Key Takeaways

• Set up all three authentication records (SPF, DKIM, DMARC) as the foundation of good deliverability
• Use double opt-in to improve list quality and reduce bounces and complaints
• Maintain clean email lists by removing bounces, inactive subscribers, and spam traps regularly
• Send relevant, valuable content that matches recipient expectations and avoids spam triggers
• Warm up new IP addresses gradually to build reputation safely
• Maintain consistent sending patterns and avoid sudden volume spikes
• Segment lists for better targeting and improved engagement
• Monitor key metrics regularly: bounce rates, engagement, complaints, and deliverability
• Follow legal requirements (CAN-SPAM, GDPR, CASL) and use permission-based lists
• Implement best practices comprehensively for best results, but start with authentication and build from there