Bounces are emails either not successfully delivered or rejected by the recipient's email provider. In this case, Flowio will automatically change the status of bounced email addresses into Cleaned. Your email campaigns could not be sent to those addresses anymore.
Why Emails Bounce?
There are several externals reasons why an email address may bounce:
Email address doesn’t exist
The contact could have provided a false address or made a typo in the address. If you are unsure, you can try correcting the email address and sending a one-off email. If the email still bounces, this address should remain suppressed.
Email is undeliverable
The email was unable to be delivered due to an error with the server, etc.
Mailbox is full
If the profile has opened emails from you in the past, they may need to empty their mailbox.
The receiving server has blocked the incoming email.
These things happen depends on your recipient's mailbox. Once the address is marked as hard bounced, it can not be changed again as initially changing the email status severely violates the Mail Client's privacy policies.
Viewing Bounce Metrics
You can view bounce details in your email campaign statistics by using the filter of the Audience > Add filter > Email campaign is Campaign's name and Email status is Cleaned
It's a good idea to keep a close eye on your bounce rate to ensure that your emails reach your contacts.
How to avoid bounces
Recheck your contact list frequently to make sure that you don't lose touch with your customers for a long time, keep your sending reputation in control and try to avoid spam filters from Mail Clients as much as possible: How to avoid Spam Filters when sending emails