When an email cannot be delivered, it bounces back. But not all bounces are the same. Understanding the difference between a hard bounce and a soft bounce helps you know what action to take and what the platform does automatically on your behalf.

Topics

• What is an email bounce?
• Hard bounces
• Soft bounces
• How the platform handles bounces
• How to reduce your bounce rate
• FAQ

What is an email bounce?

A bounce happens when an email is sent but cannot be delivered to the recipient's email server. The server sends back an automated error message explaining why. Bounces are split into two types depending on whether the failure is permanent or temporary.

Hard bounces

A hard bounce is a permanent delivery failure. The email will never reach that address, no matter how many times you try.

Common causes include:

• The email address does not exist or has a typo
• The recipient's domain does not exist
• The recipient's email server has permanently blocked your sending domain

Hard bounces are the most damaging type for your sender reputation. Inbox providers see a high hard bounce rate as a sign that your contact list is poorly managed, and they respond by routing more of your emails to spam.

What the platform does: When a contact hard bounces, they are automatically unsubscribed from the platform. They will not receive future marketing emails. This happens immediately and cannot be reversed without contacting support.

Soft bounces

A soft bounce is a temporary delivery failure. The email address is real, but something prevented the message from being delivered at that moment.

Common causes include:

• The recipient's mailbox is full
• The recipient's email server is temporarily down or unavailable
• Your email was too large
• The server flagged your message based on content or sender reputation

What the platform does: Soft bounces are monitored but do not result in automatic unsubscription. The platform will attempt to deliver future emails to that contact. However, if the same address soft bounces repeatedly, it will eventually be treated as a hard bounce and the contact will be unsubscribed.

How to reduce your bounce rate

• Use opt-in forms with email validation. This catches typos at the point of sign-up before they become bounces.
• Do not import purchased or unverified lists. These are the most common source of hard bounces.
• Send regularly. Long gaps between sends increase the chance that email addresses have become inactive or invalid.
• Monitor your bounce data. A sudden spike in bounces is worth investigating — it can indicate a list quality issue or a content problem triggering spam filters.

A good overall bounce rate sits below 2%. Hard bounces specifically should be well below this.

FAQ

A contact hard bounced but I know their email address is correct. What happened? This can happen. Some email servers temporarily reject emails in a way that the platform classifies as a hard bounce, particularly corporate mail servers with strict security policies. In some cases, the customer's IT team may need to allowlist the sending domain. Contact our support team if you believe a valid address has been incorrectly bounced.

Can I re-add a contact who hard bounced? Because the contact has been automatically unsubscribed, re-adding them requires care. If the bounce was a genuine error (for example, a server policy issue, not an invalid address), contact our support team to investigate before re-subscribing them.

Does a soft bounce mean the guest did not receive my email? Yes, for that specific send. But unlike a hard bounce, a soft bounce means delivery may succeed on a future attempt.

Any questions? Reach out to us via email at support@meandu.com.