Understanding Your Email and Campaign Metrics Reports
What is an Undeliverable?
Undeliverable emails are messages which have bounced back to the sender as permanently undeliverable
(hard bounce), most often because the email address does not exist (is invalid or no longer has an active account).
PoliteMail’s undeliverable count does not include soft bounces, which are error messages sent from the recipient’s mail server because of a temporary issue. Most often, these are delay messages, and your email will get delivered eventually (delay retries are handled automatically by the mail server). Sometimes, these are temporary issues such as mailbox is full or the mail server is down. In the case where soft bounces never get delivered, a hard-bounce message usually follows, which will be tracked.