Hard bounce is when an email is permanently fails to reach to the desired email address and returns to the sender. It mainly occurs because the email address/domain is invalid.
Having a high volume of hard bounces can affect the deliverability rates and can also set off spam filters.
That is why it is suggested to opt for an Email Service Provider that automatically removes hard bounces from the subscriber lists.
When an email bounces, it just means that it was unable to reach its intended destination for one reason or another.
A soft bounce indicates a temporary issue (server trouble, connection issues) that will be eventually resolved and your email will be deliverable following.
A hard bounce indicates a permanent problem (incorrect email address, your domain is blacklisted) making your message undeliverable.
In order to reduce hard bouncing, particularly in cold emailing, I recommend using a tool that places a lot of importance on deliverability. Clickback is such a platform that sends your campaigns using its own proprietary IPs and domains, and will clean your contact list to ensure you aren’t sending to spam traps, bad data, old email addresses, etc. This way, you won’t have to worry about landing on a blacklist, or hard bouncing when you send to addresses that don’t exist.