Hard Bounce vs. Soft Bounce: Tips for Better Email Performance

What Are Hard and Soft Bounces?

Ideally, marketing messages should land directly in recipients' inboxes, but, as any experienced marketer knows, this isn't always the case. Sometimes, they bounce back, resulting in what's known as a bounced email.

Depending on how exactly a message bounces back, it can be categorized either as a hard bounce or a soft bounce.

• Hard bounce: This bounce happens when a message is permanently undeliverable, such as when the mail address is non-existent or contains a type, or when the recipient's server has, for a variety of possible reasons, completely blocked the delivery of the message.
• Soft bounce: On the other hand, a soft bounce occurs when the delivery issue is temporary. Maybe the recipient's inbox is full, or the mail server is overloaded or the attachment included with the message is too large. In all of these scenarios, there's a variable that can be fairly easily changed to resolve the issue.

Bounce messages—both hard and soft—typically include details explaining why the email couldn't be delivered. For instance, they may indicate that the recipient's address doesn't exist, as shown in the example image where the message clearly states, "Address not found."

The message often includes a response code and additional information about the issue, which can help diagnose the problem and take appropriate action, such as list cleaning using VerifiedEmail, to improve email deliverability and sender score. The included information is the biggest difference between hard and soft bounce email messages.

Key Differences Between Hard and Soft Bounces

Both hard and soft bounces can have a severe and long-lasting impact on your mail campaigns, significantly damaging your sender reputation and leading to decreased email deliverability rates.

But if you compare soft bounces vs. hard bounces, then the latter type is generally more damaging to your email marketing efforts because they never resolve on their own. As such, they require immediate action—the removal of the offending address from your mailing list.

Soft bounces, while still problematic, offer some leeway. They often represent temporary issues that may resolve themselves. However, if soft bounces persist for a particular mail address, they can eventually be treated as hard bounces by some mail systems, so it's not like you can afford to ignore them. Instead, you should closely monitor each and every address that has caused a soft bounce and remove it if necessary.

Tips to Reduce Hard and Soft Bounces

As we've already touched upon, there are several good reasons to reduce hard and soft bounces as quickly as you can, with their negative effect on your sender reputation being the top one, followed by the increased costs if your email marketing platform charges based on the number of messages sent.

The good news is that learning how to reduce your bounce rate isn't difficult. Here are several tips that you can implement with relative ease:

• Use email verification services like VerifiedEmail to validate your mailing list on a regular basis. Such services perform a host of checks to detect both soft and hard bounces without negatively impacting your sender reputation.
• Implement a double opt-in mechanism so that subscribers confirm their mail address before you send the first message. Yes, some may skip the confirmation out of laziness or loss of interest, but that's a small price to pay for a squeaky-clean list.
• Optimize message content and design to make your messages easily deliverable across all major mail services. In particular, you should keep your HTML code clean and simple, use a balanced text-to-image ratio, avoid using spam trigger words in your subject lines and content, and be careful with attachments.
• Maintain a good sender reputation by following the best practices in email marketing, such as those described in this article. The higher your sender reputation, the lower the chance of your messages ending up in recipients' spam folders.
• Authenticate your messages using SPF, DKIM, and DMARC protocols to prove that you're a legitimate sender and not a spammer.

While these tips won't entirely eliminate hard bounce and soft bounce in email marketing, they can greatly reduce their occurrence and mitigate their impact on your campaigns.

Conclusion

Hard bounces and soft bounces in email marketing are part of the game—a game that all marketers have to play if they want to succeed in their email campaigns. Fortunately, understanding the difference between these two types of bounces doesn't take much reading, and it's similarly straightforward to implement effective strategies to manage them, such as using email verification services like VerifiedEmail.