After putting in countless hours creating the strategy, designing the graphics, writing the copy, programming, and segmenting your target audiences, you’ll definitely want to make sure the intended recipients receive your email. Unfortunately, we’ve all experienced less than 100% deliverability. Most are due to soft bounces, hard bounces, unsubscribes and spam filters, etc.

Email bounces are a normal part of email marketing. And unfortunately they’re not always unavoidable, but you can maintain a healthy email bounce rate. Some factors are in your control, but others are not, so you’ll need to adjust your tactics accordingly. Below you’ll learn the factors that make emails bounce and how to keep your bounce rate low.

An Email Bounce

Email bounces mean that your email service provider could not deliver the email you sent for several possible reasons. Better Bounces states that over 31 billion emails bounce every day, which means it happens to virtually all businesses. In most cases, something went wrong on your subscriber’s end that resulted in your email not making it into the inbox.

Why Emails Bounce

  • Your recipient’s mailbox is full. Most email providers only allow so much storage. If your subscriber has reached their limit, they can’t receive emails from you or anyone else.
  • Your IP address is bad. A bad email service provider can result in your messages not being delivered. If another marketer is sending spam from the same IP address (shared IP for example), the IP’s reputation will be damaged.
  • The subscriber blocked you. Instead of clicking “unsubscribe,” the recipient could have blocked your email address from sending emails.
  • The recipient has an auto-responder set up. Auto-responders can trigger a soft bounce until the recipient turns off this notification.
  • The server is overloaded and needs a break.
  • The receiving server doesn’t trust your content. You can control several factors that may be giving you that “email bounce” notification. (See below.)
  • The subscriber’s email address is invalid. They may have entered the wrong email address upon signup, or they gave a fake address.

Interpreting Each Bounce

Here are the different types of bounces and steps you can take to lessen the damage.

Soft Bounce

A few soft bounces are nothing to worry about. They’re normal and are included in the typical email bounce rate. A soft bounce usually means that something went wrong with the subscriber’s email server, due to the reasons above. Best of all, soft bounces are temporary.

In this case, your email server will generally attempt to resend the email several times over the course of hours or days until it manages a successful delivery. Most email service providers have a standard period for re-attempting to deliver soft bounces. If your email is still undeliverable, depending on your email service provider, the failed soft bounce might change to a hard bounce after exhausting all attempts.

If you’re getting a lot of soft bounces, adjust your campaigns and try again.

Hard Bounce

Hard bounces are serious and should be removed immediately to prevent damaging the reputation of your service provider. You cannot contact the subscriber and you shouldn’t continue to try. Hard bounces are permanent.

Hard bounces indicate the email is invalid. The subscriber could have entered the wrong information or changed their address and deleted the old one. Either way, remove the subscriber and continue sending to your remaining list.

Do not enter what you think is the correct email address. There are new privacy laws in Europe, General Data Protection Regulations (GDPR), and in California, that require subscribers to opt-in for email communications from marketers.

How to Lower Email Bounce Rates

Two to three percent is a healthy email bounce rate, depending on the size of your list. Best practice is to remove those hard bounces ASAP. With soft bounces you should take a few steps to ensure that you’re optimizing your email deliveries.

Use a Reputable Email Service Provider (ESP)

An ESP, with a full M³AAWG membership, will have a dedicated compliance and deliverability team that proactively monitors IP health and works with clients on their reputation. This drastically reduces the risk for all customers by having a robust permission-only sending policy and adhering to the leading email marketing industry standards.

Verify Your Domain

This is easy to do through your email service provider and can lower your bounce rate. It gives specific server permission to send emails from your domain addressed as your website.

Keep Images and Emails Small

Email clients may send large emails back to the sender. If you’re getting a lot of bounces, check the size of your emails. Plus, smaller emails will load more quickly on mobile devices. Here are some common limits:

  • Gmail: 25Mb
  • Outlook: 20Mb
  • Yahoo: 25Mb

Avoid Triggering Spam Filters

Spam filters update their algorithms all the time. It’s important to stay updated on what constitutes spam to avoid getting flagged and damaging your ESPs brand reputation.

Limit the size of your emails and graphics, avoid trigger words like “money” and “FREE,” avoid writing in all caps. Don’t send email campaigns with attachments or lots of exclamation points either—they could look spammy to readers and affect engagement. And low engagement can cause your emails to be filtered as spam.

Use a Signup Form and Double Opt-in

To avoid hard bounces, take advantage of double opt-in features when your subscribers sign up. After entering their email address for the first time, each subscriber will receive an email that asks them to verify their email. Each subscriber physically has to click “yes” or follow a specific link to sign up. This eliminates invalid emails right away. Plus, only people who want to hear from you get your emails.

Use an Email Bounce Checker

Most Email Service Providers (ESPs) and marketing automation platforms, as well as Better Bounces will offer email bounce diagnostics to understand error codes and what went wrong so you can improve your deliverability. Your email service provider should also help with special tools and information about maintaining a healthy email bounce rate.

Create a Master Suppression List

Keep a list of all bounces and unsubscribes. Before sending any email, be sure to scrub your list against your suppression file to remove any unwanted emails.

Cleanse Your List

Sending emails to invalid addresses of hard bounces can damage the reputation of your IP address and create even more bounces. Keep your subscriber list clean by removing hard bounces as soon as possible. Email hygiene is imperative to the long-term success of your email marketing efforts.

Have your list cleansed through a professional service to remove known bounces and spam traps. Spam traps are especially harmful to your online reputation and removing them will help keep you from being blacklisted.

Remove Unengaged Subscribers

Remove email addresses from your database that haven’t produced engagement (clicked or opened) in the past 6 months. You may decide to follow-up on these emails with a re-engagement campaign in the future, but don’t continue sending them regular emails.

Remove Unsubscribes

Your reputation at risk when you continue to send emails to a prospect that has already asked to be removed. It is critical that you remove these emails immediately to comply with CAN-SPAM requirements.

Filter Out Certain Domains and Addresses

Consider filtering out certain domains if they have caused delivery problems in the past. Some domains (.gov, .biz, .edu, .mil, etc…) can be more problematic than others. Don’t mail to any address with ‘Postmaster’, ‘Info’, etc.

Keeping your customer data clean and up-to-date can seem daunting. However, it has never been more critical for email deliverability. Internet Service Providers (ISPs) do their best to protect clients from unwanted emails and spam. These ISPs determine whether your email ever makes it to the intended inbox. Email hygiene is imperative to the long-term success of your email marketing efforts.

Ready to take your email marketing to the next level with marketing automation? Contact Lori at 877.447.0134 or

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