What is a soft bounce?

As an email marketer, deliverability is one of your most important considerations, as the success of a campaign or strategy hinges on your ability to land your content in your recipients’ inboxes.

Unfortunately, there are a variety of issues that may occur through no fault of your own, but that will still negatively affect your deliverability as a sender. Email bounce backs can be one of these issues, with the soft bounce a common subtype.

Want to jump ahead? What is a bounce? How does a soft bounce differ from a hard bounce? How to achieve optimal bounce rates Use a double opt-in Maintain your mailing lists regularly Send carefully-crafted content Utilize A/B testing Conclusion

What is a bounce?

Before we explore the concept of a soft bounce, let’s first establish what a “bounce” is in email marketing.

An email bounce occurs when a sent email is unable to be delivered to the intended recipient’s inbox for one reason or another. Essentially, it’s the email equivalent of a letter “being returned to sender.”

In cases where an email bounces, you, the sender, will receive a notification that your message has not been sent, and the receiving mail server will typically respond with an SMTP (Simple Mail Transfer Protocol) reply containing a code that indicates the cause of the issue.

There are two types of bounce: a soft bounce and a hard bounce.

How does a soft bounce differ from a hard bounce?

The fundamental difference between a soft bounce and a hard bounce is the reason behind the delivery issue, and this is reflected in the codes produced by the recipient’s email server in the SMTP dialog.

Hard bounces, denoted by 5XX codes, are the result of a permanent issue, meaning that the email has been definitively rejected. These permanent reasons  usually occur when the recipient’s email address is  invalid or non-existent.

Soft bounces, on the other hand, are denoted by 4XX codes and signify temporary issues. In the case of a soft bounce, the message has managed to reach the recipient’s email server before being rejected, and you, the sender, can attempt to re-send the message at a later point.

There are a variety of potential causes for a soft bounce. For instance, the receiving email server may be down for maintenance or may have received a high volume of messages in the short term. In some cases, it could simply be that the recipient’s mailbox is full or the file that you are sending is too large.

While these issues aren’t necessarily major concerns, problems can occur when a sender experiences a repeated sequence of soft bounces without resolution. When this happens, email providers convert a soft bounce into a hard bounce, at which point deliverability is impacted in a meaningful way.

For this reason, it’s advisable to follow best practices to keep your bounce rate under control.

How to achieve optimal bounce rates

When dealing with bounced emails, a good rule of thumb is to aim for a bounce rate of 2% or less. A bounce rate that exceeds the 2% threshold warrants immediate attention so you can fix the problem as soon as possible. To maintain a low bounce rate and avoid this situation, there are some things you can do:

1. Use a double opt-in

A double opt-in requires subscribers to confirm their participation in your email campaigns, so it provides certain assurances concerning deliverability. Firstly, it ensures that your subscribers are engaged and are unlikely to report your emails as spam. Secondly, it helps confirm the validity of their email address, ensuring that you don’t run into delivery issues, like bounces

2. Maintain your mailing lists regularly

Using a double opt-in can lower your bounce rate by helping keep your email list healthy, but a degree of upkeep is still required to maintain good list hygiene. By taking the time to regularly purge inactive and invalid email addresses from your list, you can help keep your bounce rate under control and prevent deliverability issues.

Depending on the frequency of your send-outs, you may want to do this more or less often, but it is recommended to conduct email cleaning at least once every six months.

3. Send carefully-crafted content

Nowadays, a large proportion of all emails sent worldwide are spam. This means that spam filters are more strict than they have ever been. Small details can see your emails diverted from their intended course, so it pays to spend time refining your email marketing content. Using proper structures and mechanics in your subject lines, subheaders, and marketing copy can help you steer clear of spam filters and keep your bounce rate low.

4. Utilize A/B testing

A good way to keep bounce rates low is to conduct A/B testing before performing bulk send-outs. This way, you can create two alternate versions of an email to determine which one will perform better before you decide which to send out. Using A/B testing helps you prevent issues before they occur.

Conclusion

It sounds simple, but taking a broadly holistic approach to email marketing is generally the best course of action. By taking the time to create meaningful, engaging, and sound content that has been thoroughly quality-controlled, you lower the likelihood of issues, both from spam filters and user reports. Combine this with good email hygiene and a sound subscription process, and you’ve got a recipe for success in email marketing.

When it comes to monitoring your email bounce rate, your email marketing platform will provide tracking functionality to help you. This way, you can know where you stand in terms of hard and soft bounces, and should an issue arise, you will be able to take the appropriate measures to remedy the situation.