Bounced emails are emails that are not delivered to the mailbox provider or the ISP of the recipient. Bouncing may be a soft bounce, technical bounce, block bounce, hard bounce, or an unknown bounce.
When a mail server rejects an email message, it becomes a bounced email. A bounced email has not gotten to the intended destination.
There are two types of bounce – the soft bounce and the hard bounce. It is a hard bounce when the email address is permanently closed and prohibited from receiving electronic emails. It is a soft bounce if the closure is temporary, perhaps due to a full inbox or server outage. It is common for email service providers to label soft bounces, with three failed sends, a hard bounce.
An email message may be bounced for different reasons. For instance, it may be due to server outages, a full inbox, incorrect or non-existent receiving email address, or a poor sender reputation emanating from spam complaints. Other reasons include a restrictive DMARC record for the sending domain or the presence of flagged content in the message content.
Email bounces are not considered a huge problem. A good way of reducing bounce rates is to send to only opted-in email addresses and sending regularly. Other useful tips include decluttering your sending lists by removing unengaged emails or adopting a double opt-in process to obtain emails.