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Email Deliverability & Authentication

Proper email authentication is essential for ensuring your emails reach the inbox. This guide explains how Engage Studio helps you authenticate your emails and maintain a strong sender reputation.

Why Authentication Matters

Email authentication helps mailbox providers (Gmail, Outlook, Yahoo) recognize you as a legitimate sender and deliver your emails to the inbox instead of spam. Engage Studio automates most of the authentication process, but understanding the basics helps you maintain high deliverability.

Authentication Protocols

SPF (Sender Policy Framework)

SPF verifies that emails are sent from authorized mail servers for your domain.

What it does:

  • Lists which servers can send email on behalf of your domain
  • Helps prevent spammers from forging your domain

How Engage Studio handles it:

  • Automatically generates the SPF record when you configure your domain
  • You add the provided TXT record to your DNS settings
  • No ongoing maintenance required
Best Practice

Use a subdomain like mail.yourdomain.com for marketing emails to keep authentication separate from your corporate email.

DKIM (DomainKeys Identified Mail)

DKIM adds a digital signature to your emails to verify they haven't been altered in transit.

What it does:

  • Signs each email with a cryptographic signature
  • Receiving servers verify the signature using your public key

How Engage Studio handles it:

  • Generates encryption keys automatically
  • Signs every outgoing email
  • Provides the DNS record to publish your public key
Best Practice

Verify your DKIM records are active before sending production emails.

DMARC (Domain-based Message Authentication, Reporting & Conformance)

DMARC tells receiving servers what to do when SPF or DKIM checks fail.

What it does:

  • Sets a policy for handling failed authentication
  • Provides reports on your email authentication performance

DMARC Policies:

PolicyWhat happensWhen to use
p=noneNo action - emails deliver normally, but you get reportsStart here - Monitor without affecting delivery
p=quarantineSuspicious emails go to spam folderAfter achieving >95% authentication pass rate
p=rejectFailed emails are blocked completelyAfter long-term monitoring confirms stability

How Engage Studio handles it:

  • Provides a recommended DMARC record during domain setup
  • You can configure reporting emails to monitor authentication
Important

If your main domain already has a DMARC record, you may not need to configure the one provided by Engage Studio. Check with your IT team.

IP Warming & Reputation

Understanding IP Warming

IP warming is the process of gradually building a positive sending reputation with mailbox providers.

Why it matters:

  • New IP addresses have no reputation with mailbox providers
  • Sending large volumes immediately from a new IP looks suspicious
  • Reputation is earned over time through consistent, high-quality sending

How Engage Studio Manages IPs

Engage Studio uses Amazon SES managed IP pools, which automatically handle IP allocation based on your sending volume:

  • Starting out (low volume): Your emails are sent from shared IPs that already have established reputation. No warming needed.
  • Growing (medium volume): As your volume increases, Amazon SES may transition you to dedicated IPs and automatically warms them.
  • Established (high volume): High-volume senders (typically 100,000+ emails/day) get dedicated IPs with isolated reputation.

The key benefit: You don't need to manually warm IPs. Amazon SES handles the entire process automatically.

Best Practices for Deliverability

Build Your Reputation

Even with automated IP management, follow these practices:

1. Start with engaged subscribers

  • Send first to people who recently opened or clicked your emails
  • Avoid sending to old, inactive lists right away

2. Increase volume gradually

  • Don't jump from 1,000 to 100,000 emails overnight
  • Increase volume steadily over days and weeks
  • Watch for sudden drops in engagement or increases in bounces

3. Maintain consistency

  • Send regularly (daily or weekly) rather than sporadic bursts
  • Keep sender names and addresses consistent
  • Avoid sudden changes in content style or format

Keep Your List Clean

Remove bad addresses:

  • Hard bounces (invalid addresses)
  • Spam complaints
  • Addresses that never engage

Validate new subscribers:

  • Use double opt-in to confirm email addresses
  • Validate email format before adding to your list

Monitor Key Metrics

Track these metrics to maintain good deliverability:

MetricTargetWhy it matters
Bounce rate<2%Too many bounces signals poor list quality
Complaint rate<0.1%High complaints damage sender reputation
Open rateIndustry averageSudden drops indicate deliverability issues
EngagementSteady or growingShows recipients value your emails

Create Quality Content

Avoid spam triggers:

  • Excessive use of words like "FREE", "LIMITED TIME", "ACT NOW"
  • ALL CAPS subject lines
  • Too many exclamation points!!!

Balance your email:

  • Mix text and images (don't send image-only emails)
  • Include a clear unsubscribe link
  • Make emails mobile-friendly

Stay compliant:

  • Include your physical mailing address
  • Honor unsubscribe requests promptly (within 24-48 hours)
  • Only email people who gave permission

Troubleshooting

Emails Going to Spam

Check these first:

  1. Verify SPF, DKIM, and DMARC are passing (check email headers)
  2. Review content for spam trigger words
  3. Confirm you're sending to engaged subscribers
  4. Check your sender reputation using Google Postmaster Tools

High Bounce Rates

If you're seeing >5% bounces:

  1. Remove invalid email addresses immediately
  2. Implement email validation at signup
  3. Verify DNS records are configured correctly
  4. Never use purchased or scraped email lists

Low Engagement

If open/click rates are dropping:

  1. Improve subject lines and preview text
  2. Test different send times
  3. Segment your list by behavior and interests
  4. Re-engage inactive subscribers with a win-back campaign
  5. Remove subscribers who haven't engaged in 6+ months

Monitoring Tools

Built into Engage Studio

  • Email Delivery Events - Track sent, delivered, bounced, and complained events
  • Email Error Events - Diagnose specific delivery failures
  • Domain verification status - Monitor SPF/DKIM/DMARC in Sending Configurations

External Tools

  • Google Postmaster Tools - Monitor domain reputation, spam rate, delivery errors for Gmail
  • Microsoft SNDS - Check your IP reputation for Outlook/Hotmail
  • DMARC Analyzers (dmarcian, Postmark) - Parse DMARC reports to identify authentication issues

Next Steps

  1. Set up authentication: Follow the Domain Configuration guide to configure SPF, DKIM, and DMARC
  2. Configure sender profiles: Create sender profiles with proper unsubscribe headers (Sender Configuration)
  3. Start sending: Begin with engaged subscribers and gradually increase volume
  4. Monitor performance: Watch delivery metrics and adjust your strategy as needed