Maximising Email Deliverability: The Importance of Controlled Campaign Volume

Platforms like Gmail and Outlook respond quickly and aggressively to large volumes of emails from a single domain. This can significantly impact both immediate and long-term email marketing success.

Short-Term Impacts

1. Temporary Bouncing of Emails
   Gmail and Outlook may temporarily reject or “soft bounce” emails when they detect unusually high traffic from a single domain. This is a protective measure to prevent spam.
2. Throttling
   Email providers can slow down or cap the number of emails they accept from your domain within a specific time window.
3. Snowball Effect
   When bounce rates spike, email providers may classify the entire campaign as problematic, further reducing deliverability—even for valid addresses.
4. Increased Spam Probability
   Even if emails eventually get delivered, initial high bounce rates often push them directly to the spam folder for many recipients.

Medium-Term Impacts

1. Reputation Degradation
   Gmail, Outlook, and other providers track the reputation of sending domains and IP addresses. Repeated instances of high bounce rates or aggressive sending lead to declining reputation scores, even if immediate issues are resolved. A poor reputation makes future campaigns harder to deliver successfully.
2. Deliverability Challenges
   Once flagged, your domain may face ongoing deliverability problems, such as emails being automatically routed to spam or promotion folders. This issue can persist even after cleaning up your email list and improving sending strategies.

How to Avoid These Issues: Segmented Sending

Segmented sending is the single most effective way to prevent these problems. While there is no published audience size rule, our experience shows that keeping your total audience below 20,000 recipients per campaign yields the best results.

Example Approach:

If your database includes 100,000 recipients, split it into five smaller groups of 20,000. Use database folders or Roi-AI triggers to send these batches several days apart.

Benefits of This Approach:

• Better Deliverability: Lower bounce rates and reduced spam classification risks.
• Higher Engagement: Manageable responses and interactions lead to better team performance and campaign success.
• Enhanced Reputation: Gradual, high-quality email traffic builds trust with providers like Gmail and Outlook.

If you need assistance with segmentation or batch scheduling, please reach out to the Roi-AI Support team—we’re happy to help!