When sending cold emails, email marketing, and newsletters, you need to be aware of two types of bounces: soft bounces and hard bounces.
A soft bounce occurs when the email is temporarily unable to be delivered to the recipient. This could be due to reasons such as a full inbox or a temporary issue with the email server. In most cases, the email will be retried for delivery over a period of time before eventually being marked as a hard bounce.
A hard bounce, on the other hand, is a permanent issue that occurs when you send an email to either a deleted email address or an invalid one. This could happen if the recipient has closed their account, changed their email address, or if you made a mistake in typing the email address. When an email bounces back as a hard bounce, it will not be delivered, no matter how hard you try.
It's important to keep an eye on your bounce rates because if both soft and hard bounce rates are too high, it can negatively impact your email deliverability and significantly decrease your domain reputation.
High bounce rates can be a sign to email service providers (ESPs) that your email list is outdated, low-quality, or that you're not following best practices. This could lead to your emails being flagged as spam and sent to the recipient's junk folder or, even worse, being blocked entirely.