What is Rate Limiting?
Rate limiting is a technique used to control the number of
emails sent to an email service provider (ESP) within a specific period. It helps to manage the flow of emails and prevent overwhelming the ESP servers, ensuring better
deliverability and avoiding being flagged as
spam.
Why is Rate Limiting Important?
Rate limiting is crucial because it helps maintain a positive sender reputation, which is essential for
email deliverability. Sending too many emails too quickly can trigger spam filters and result in emails being blocked or sent to the spam folder. Additionally, rate limiting can prevent server overload, ensuring that emails are delivered efficiently.
How Does Rate Limiting Work?
Rate limiting typically works by setting a maximum number of emails that can be sent within a specific timeframe. For example, an ESP might allow 100 emails per minute. If you exceed this limit, additional emails will be queued or rejected. This ensures a steady flow of emails and reduces the risk of being flagged as spam.
Per-hour rate limiting: This sets a limit on the number of emails that can be sent per hour.
Per-day rate limiting: This sets a limit on the number of emails that can be sent per day.
Some ESPs may also offer more granular control, such as per-minute or per-second rate limits, depending on their infrastructure and policies.
How to Determine the Right Rate Limit?
Determining the right rate limit depends on several factors, including your email list size, the
engagement levels of your subscribers, and the policies of your ESP. It's often advisable to start with a conservative rate limit and gradually increase it based on the performance and feedback from your ESP.
Understand your ESP's rate limit policies and configure your sending accordingly.
Monitor your email delivery reports to identify any issues related to rate limiting.
Gradually scale your email sending volume to avoid sudden spikes.
Segment your email list to send more targeted and relevant emails, reducing the overall volume.
Your emails may be delayed or queued for later delivery.
Your emails may be rejected, resulting in delivery failures.
Your sender reputation may be negatively impacted, affecting future email deliverability.
Can Rate Limiting Affect Email Campaign Performance?
Yes, rate limiting can affect the performance of your
email campaigns. If not managed properly, it can lead to delayed email deliveries, reduced open rates, and lower engagement. However, when implemented correctly, rate limiting can improve deliverability and ensure that your emails reach the inbox rather than the spam folder.
How to Monitor and Adjust Rate Limits?
Regularly monitor your email delivery reports to identify any issues related to rate limiting. Use analytics tools to track your email performance and adjust your rate limits accordingly. Communicate with your ESP to understand their rate limit policies and get recommendations for optimizing your email sending strategy.