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

Optimal Set up:

• Make sure you are compliant and your email setup is correct.
  • Check for compliance.
  • Test email set up.
• Ensure audience collection points are clean.
  • Use double opt-in, if possible.
  • If not, use a single opt-in with captch at the signup point to avoid bot signups.
  • Do not send marketing/promotions to users if they have not explicitly signed up.
    • Check user collection best practices.
• Ensure email send frequency is proportional to end user’s 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 unsubscribed.
• Set correct expectations and be open and clear.
  • Set correct expectations while collecting users and stick to those.
  • Subject lines and pre-header text must never mislead the users about the content of the email.

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.
  • Check warm-up best practices.
• Use the correct RPM to throttle the emails.
  • If you send too fast without ramping up, it will result in delivery issues.
  • Refer to RPM recommendations.
• Do not suddenly increase volume.
  • Peak season campaigns tend to include less 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 instead of resuming after inactivity.
  • IPs and domains get cold when inactive.
    • 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).

Dynamic Strategy

• Maintain a 70:30 ratio for Active v/s Inactive Users.
  • The major portion of the target criteria should be active users.
  • This helps keep the overall negative engagement low.
• Send event-based personalized campaigns like event-triggered and flow campaigns.
  • Use cases for e-commerce brands can be found here.
• Make sure content is relevant to the users.
  • Sending irrelevant content makes people lose interest in the sender.
• If engagement levels drop, reduce send frequency and send targeted content.
  • Survey to find reasons for disinterest.
• Suppress inactive users if there has been no engagement in 6+ months (or less/more depending on the industry.)
  • ISPs like Comcast, Yahoo, and so on, 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

• In case of issues:
  • Deferrals i.e. rate limited by ISP.
    • Use lower RPM
    • Look into 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
    • Check whether the content is relevant to each segment.
  • Low opens/clicks
    • Send only to email openers
    • Review the target audience
    • Review FC settings
    • Ensure content v/s segment relevancy.
    • Pause and monitor.
• In case of domain reputation issues, check here.