Email Deliverability Technical Guide: SPF, DKIM, DMARC & Beyond
What is the complete guide to Email Deliverability Technical : SPF, DKIM, DMARC & Beyond?
Quick Answer: Email deliverability is the foundation of successful email marketing. This technical guide provides step-by-step instructions for implementing authentication protocols, improving sender reputation, and ensuring your emails reach the inbox.
Email Deliverability Technical Guide: SPF, DKIM, DMARC & Beyond
Email deliverability is the foundation of successful email marketing. This technical guide provides step-by-step instructions for implementing authentication protocols, improving sender reputation, and ensuring your emails reach the inbox.
"How many times should I follow up?"
How many follow-ups should I send? Send 3-5 follow-up emails spaced 3-7 days apart. Each follow-up should provide new value and have a different angle. Stop if you receive a response or after the 5th attempt.
💡 Pro Tip: Each follow-up should add new value, not just repeat the same message.
Email Authentication Trinity
SPF (Sender Policy Framework)
What it does: Specifies which mail servers can send email for your domain
Implementation:
; Basic SPF record
v=spf1 include:_spf.google.com include:sendgrid.net -all
; Explained:
; v=spf1 - SPF version
; include:_spf.google.com - Google Workspace
; include:sendgrid.net - SendGrid ESP
; -all - Reject all others
Common Issues & Solutions:
- ✓DNS lookup limit (10 lookups max)
- ✓Use SPF flattening tools
- ✓Consolidate email services
- ✓Monitor with SPF surveys
DKIM (DomainKeys Identified Mail)
What it does: Cryptographically signs emails to verify sender and content integrity
Implementation Steps:
- ✓Generate DKIM keys (2048-bit recommended)
- ✓Add public key to DNS
- ✓Configure email server to sign
; DKIM DNS record example
selector._domainkey.yourdomain.com. IN TXT "v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4..."
DMARC (Domain-based Message Authentication)
What it does: Tells receivers what to do with emails that fail SPF/DKIM
Progressive Implementation:
; Stage 1: Monitor only
v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com
; Stage 2: Quarantine suspicious
v=DMARC1; p=quarantine; pct=50; rua=mailto:dmarc@yourdomain.com
; Stage 3: Full enforcement
v=DMARC1; p=reject; rua=mailto:dmarc@yourdomain.com; ruf=mailto:forensics@yourdomain.com
Continue reading for IP warming strategies, reputation monitoring, and advanced deliverability tactics.
Frequently Asked Questions
What is the best time to send cold emails?
The best time to send cold emails is Tuesday through Thursday, between 8-10 AM and 2-5 PM in your recipient's timezone. Avoid Mondays and Fridays when inboxes are typically fuller.
How many follow-ups should I send?
Send 3-5 follow-up emails spaced 3-7 days apart. Each follow-up should provide new value and have a different angle. Stop if you receive a response or after the 5th attempt.
How can I improve my email open rates?
Focus on compelling subject lines (6-10 words), personalize the sender name, ensure good sender reputation, and send at optimal times. A/B test different approaches to find what works for your audience.
What makes a good email call-to-action?
A good CTA is specific, low-commitment, and valuable to the recipient. Instead of 'Let me know if interested,' try 'Would you be open to a 15-minute call Tuesday to discuss how we helped Company X achieve Y?'
Industry Statistics and Benchmarks
- ✓Average B2B email open rate: 21.5% across industries
- ✓Click-through rate: 2.62% for personalized emails vs 1.1% for generic
- ✓Reply rate: Well-crafted cold emails achieve 8-12% reply rates
- ✓Conversion rate: Top performers see 3-5% meeting booking rates
- ✓ROI: Email marketing delivers $42 for every $1 spent
Best Practices for Success
1. Research Your Prospects
Spend 2-3 minutes researching each prospect. Look for recent company news, personal achievements, or shared connections. This investment pays off with 3x higher reply rates.
2. Write Compelling Subject Lines
Keep subject lines between 30-50 characters. Use curiosity, personalization, or value props. Avoid spam triggers like "Free," "Guarantee," or excessive punctuation.
3. Focus on Value, Not Features
Instead of listing what your product does, explain what it means for them. Transform features into benefits that address their specific pain points.
4. Make CTAs Crystal Clear
One email, one ask. Whether it's booking a call, downloading a resource, or simply replying, make your call-to-action specific and easy to complete.
5. Test and Iterate
A/B test different elements: subject lines, opening lines, value props, and CTAs. Track metrics and continuously improve based on data.
Recommended Tools and Resources
Email Generation Tools
- ✓Folderly EmailGen AI: Generate personalized cold emails based on 15,000+ proven templates
- ✓Subject Line Generator: Create attention-grabbing subject lines optimized for open rates
- ✓Follow-Up Sequence Builder: Automate your follow-up process with AI-generated sequences
Email Verification and Warming
- ✓Email Verification: Ensure deliverability by verifying email addresses before sending
- ✓Domain Warming: Gradually increase sending volume to build sender reputation
- ✓Spam Testing: Check your emails against spam filters before sending
Vladyslav Podoliako
Founder & CEO
Founder & CEO of Folderly, the AI-powered email marketing platform.
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