Best Practices for Email Deliverability

Proven best practices to improve email deliverability, from authentication setup and audience data collection to engagement-based frequency.

Follow the best practices below to achieve and maintain good email deliverability.

Set up Your Email for Optimal Deliverability

• Ensure your email setup is correct and compliant.
  • Check for compliance.
  • Test email set up.
• Collect audience data accurately.
  • Use double opt-in, if possible.
  • If not, use a single opt-in with a captcha at the signup point to avoid bot signups.
  • Do not send marketing/promotions to users if they have not explicitly signed up.
    • Review user collection best practices.
• Align email frequency with user engagement levels.
  • Send less frequently to less engaged users.
  • Consider retargeting campaigns for unengaged users.
  • Use Frequency capping to limit the emails sent per user per day/week.
    • Sending too frequently results in user fatigue, which increases spam complaints and unsubscribes.
• Set clear expectations for your email communications.
  • Communicate your email frequency and content clearly when collecting user information, and then stick to those expectations.
  • Ensure subject lines and pre-header text accurately reflect the email content.

Maintain Steady Sending Patterns

• Maintain steady sending patterns to ensure IP and domain remain warmed up.
  • Send at least 1 campaign a week to active users.
  • Send at least 1 campaign every 2-3 weeks to the ramped-up volume / all opted-in users [barring the suppressed inactive users].
• Make sure you are warmed up to send the intended volume.
  • Review warm-up best practices.
• Throttle emails using the correct RPM.
  Sending too quickly without warming up your volume can lead to delivery issues. For more information, refer to RPM recommendations.
• Do not suddenly increase volume.
  • Peak season campaigns tend to include fewer active/inactive users. Prepare for peak season mailings at least 6 weeks in advance.
  • Important announcements can be sudden. Make sure these are text-only and throttled/split over the day/s well.
• Ramp up sending volume after periods of inactivity.
  • • Inactive IPs and domains can become ‘cold’ and lose reputation.
    • Start slowly by sending to highly engaged users.
    • Slowly expand to other users with lower email engagement.
    • Do not send higher volumes at once.
    • Send to email openers only, with higher throttling (low RPM).

Implement Dynamic Strategy

• Maintain a 70:30 ratio of active versus inactive users.
  Focus the majority of your target audience on active users. This helps keep the overall negative engagement low.
• Send event-based personalized campaigns, like event-triggered and flow campaigns. Refer to Use cases for e-commerce brands.
• Ensure content relevance for users. Irrelevant content makes users lose interest in the sender.
• If engagement levels drop, reduce send frequency and send targeted content. Survey users to understand their disinterest.
• Suppress inactive users if there has been no engagement in 6+ months (or less/more depending on the industry.)
  • Internet Service Providers (ISPs), such as Comcast and Yahoo, may disable unused mailboxes.
  • If mailbox providers themselves have policies to suspend users, it’s imperative that the sender also have strategies to suppress them.

Monitor and Revise Your Email Strategy

Address common deliverability issues:

• • Deferrals: Internet Service Providers (ISPs) may rate limit your sends.
    • Use lower RPM
    • Examine your sending patterns.
    • Pause for a day, let the IPs rest, and raise a ticket with postmaster support.
  • High user-reported spam complaints/unsubscribes:
    • Reduce sending frequency
    • Verify content relevance for each segment.
  • Low opens or clicks
    • Send only to email openers
    • Review the target audience
    • Review Frequency Capping (FC) settings
    • Ensure content v/s segment relevancy.
    • Pause and monitor.
• In case of domain reputation issues, refer to Issues with Domain Reputation and Preventive Measures.