There are a few ways to reduce your bounce rates before sending. The most common reasons why bounces occur are due to improper subscriber list handling and opt-in processes.

• Use a double opt-in process
  When collecting your subscribers via an online form (or alternative method), you may want to implement a double opt-in process where a subscriber needs to confirm their subscription before being successfully subscribed. This will ensure that your subscribers are genuine and the email used is not invalid from the start.

• Have a clear unsubscribe or 'update your details' link in emails
  Ensure your subscribers can efficiently and easily unsubscribed or update their email address. This will allow you to prevent bounces before they occur.

• Engage with dormant lists
  If you have subscribers in separated lists, try to keep communication consistent with each list. No list should lay dormant for months-years between communications as this may result in an unexpectedly high bounce rate for single sends.