Bounce management is very important for email marketers trying to achieve inbox success.  You should have methods in place to automatically capture bounce data and should review that data on a regular basis to keep your lists clean.  I often get many questions relating to bounce management and deliverability.  Here are few of those:

What is the difference between a hard bounce and a soft bounce?

A hard bounce means that the recipient’s mail server indicates a permanent delivery failure and retried delivery attempts will not be successful.  An example of a hard bounce would be a bad mailbox.  You should strive for a hard bounce rate of no more than 5%.  Hard bounce rates that exceed 7% are cause for concern and should be immediately addressed.

A soft bounce is a valid email address that has been returned as temporarily undeliverable due to many different circumstances such as mailbox full or swamped mail servers.  A good rule is to scrub from your list any address that has consistently soft bounced at least three times over a certain period of time.

Can having too many hard or soft bounces hurt my deliverability?

The short answer is yes.  Too many hard bounces in your list could indicate an old list and too many soft bounces could indicate that you are being rate limited at an ISP due to complaints or traffic.  ISPs monitor and track those senders that send to large amounts of bad mailboxes, as well as those who get soft bounced due to complaints.  This could also affect your reputation on the IP and the domain that you are sending from.

When you don’t confirm your opt-in subscribers or clean your list often, you run the risk of piling up many undeliverable email addresses.  Here are some ways to help:

  • Confirm opt-ins.  Single opt-in is better than nothing, but confirmation, in which the subscriber has to verify their request, is the best way to try and remove typing mistakes.
  • Practice regular list hygiene.  Before your email campaign, run a program to find all malformed e-mail addresses (e.g.,;,, etc.).  Your email software should also try to pull out any other invalid email addresses, such as nonexistent mailboxes.