Here you will learn why sent emails don’t match total delivered bounced and unsubscribed in MailBluster reports. Many marketers notice differences between the number of emails sent and the final counts of delivered, bounced, or unsubscribed. This happens because of the way email servers handle delivery and reporting.
1. Permanent Bounce/ Hard bounce: This occurs when an email cannot be delivered due to an invalid email address or a non-existent domain. In such cases, the email server considers the bounce as permanent and won’t attempt further deliveries to that address.
2. Temporary Delivery Issue/Soft bounce: This might happen due to a full recipient mailbox, the recipient server being temporarily down, or other transient issues. In these cases, MailBluster retry sending the email after a certain period.
The rest of your emails might face temporary Delivery Issue/Soft bounce event.
When a soft bounce event happens, your SMTP provider continuously retries to deliver your email for 12 hours before giving up. There is no limit of retries during this 12-hour interval and as long as the ISP recovers, your email will be delivered.
You can learn more bounce types from the AWS SES document here:
https://docs.aws.amazon.com/ses/latest/DeveloperGuide/notification-contents.html#bounce-types
In summary, when sent emails don’t match total delivered bounced and unsubscribed, it’s usually because of hard bounces, soft bounces, or unsubscribes after sending. Understanding these reasons helps you analyze reports more accurately and maintain a healthy email list. To reduce mismatches, clean your list regularly, verify email addresses, and avoid sending to invalid or risky contacts. Doing this improves deliverability and ensures that your reports better reflect reality.