Bounced - Expired emails are emails that are unable to be delivered within 72 hours.
If an email bounces, we will retry for up to 72 hours. If the email is unable to be delivered within the last 72 hours, it will expire and be marked as Bounced - Expired.
Bounced emails are commonly due to SMTP 4XX
errors or SMTP 5XX
errors, which cause an email to be undeliverable: