Acceptable Bounce Rates and Industry Standards

For email marketers, bounces are an inevitable part of life. Bounces, or rejected emails, can be temporary or permanent and may be caused by a number of factors. Hard bounces indicate a permanent or terminal failure (user not found, bad domain), while soft bounces represent transient or temporary factors like a full inbox or server error.

We often get asked by clients to provide the ideal bounce rate, and truthfully the answer is zero. In a perfect world, mail would never be rejected and all your messages would be delivered. By contrast, bounces are unavoidable in the real world so let’s talk about what to look for in regards to bounce rates.

There is no true industry standard for an acceptable bounce rate. ISPs and mailbox providers track the percentage of mail sent to their network that bounces, but the thresholds for each provider are different and are not publicly shared. Some providers even use dynamic thresholds depending on other factors like reputation and volume.

The best senders have hard bounce rates below 1%, but even a rate of 3% is unlikely to cause serious issues as long as list acquisition best practices are followed and all other metrics look good.

Most email service providers (ESPs) also monitor bounce rates and may take action if your rates creep too high. A hard bounce rate of 5% or above is enough to cause most ESPs to reach out or take action to restrict your sending, although some allow as high as 8% hard bounces.

While these numbers refer specifically to hard bounces, your soft bounce rates should stay low as well. Industry views on soft bounces vary, but a total bounce rate (hard plus soft) above 10% is often cause for concern.

My bounce rates are too high. Now what?

If you find your bounce rates need attention, there are a few steps you can take:

1. Review your opt-in practices. Double or confirmed opt-in provides the most insulation against invalid addresses, but there are other alternatives as well. Consider implementing real-time email verification on sign-up and/or provide an option for subscribers to enter their address a second time.

2. Forget the purchased lists. Purchased, rented, or other third-party lists could have been compiled anywhere – regardless what a list vendor might tell you. If a contact didn’t specifically ask for your emails, they’re only going to cause you delivery headaches. Get rid of them.

3. Send a welcome message right away. Even if you don’t use double opt-in, sending an immediate welcome message helps weed out problematic addresses right out of the gate. During the sign-up process, you should also tell the subscriber to expect this email. That way, if they don’t receive it in their inbox, they’ll go looking in their junk folder or reach out to you for help.

What if my bounce rates aren’t so bad?

If your bounce rates are low, that’s a great start…but it’s no guarantee you won’t see delivery troubles. One way to ensure your bounce rates stay low is to use automated suppression to remove bounced addresses from your active mailing list.

  • Hard bounces. For these more permanent bounces, industry standards typically dictate removing records after 1 occurrence, or 2 at most. This includes bounce types like User Not Found or Bad Domain.
  • Soft bounces. Since soft bounces are more transient, it’s not always a good idea to suppress them right away. If you do want to suppress soft bounced addresses, you should allow at least 3-5 occurrences before suppressing. This ensures that temporary circumstances like a full inbox or a server outage won’t cause good, active members to be suppressed.

The best way to keep bounces low is to start with a list of subscribers acquired through a clear opt-in, and keep your list clean by suppressing bounced addresses. By doing that you’ll also be decreasing your chances of other delivery issues, which means that more of your subscribers will actually receive your message.