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How to reduce the bounce rate on your mailing lists

How to reduce the bounce rate on your mailing lists

Bounces represent real challenges for those who deal with bulk email lists.

This is because they directly interfere with the deliverability of campaigns. In other words, a list full of bounces won’t reach the recipient’s inbox.

And by not completing its objective, the email marketing has compromised all its investment, since the audience didn’t even receive the message!

To avoid bounces, you need to build a solid email list that provides real leads with the possibility of progressing through the marketing funnel from the very first contact, when the audience is still a prospect.

Knowing whether a contact is valid or not, through the email validation service, is crucial to building a healthy base, as the verification algorithm identifies all bounces.

And with a clean list, email marketing can fulfill its objective of reaching the inbox.

Do you know how to create an email base capable of generating leads? Watch our webinar full of tips on the subject!

To understand the concept of bounce and what it represents, you need to answer a simple question:

Why does your list have bounces?

Obviously, email verification will remove all risky emails from your lists. But the question is how they appear in your databases.

Here are some likely reasons:

  • Invalid or non-existent emails: these are those with typing errors and usually come from registration forms that haven’t gone through real-time email verification.
  • Your emails are exceeding the size of the images required by the providers, which is why they are not delivered to the inbox.
  • The recipient’s mail server is experiencing technical problems. For this reason, the message bounces.
  • The internet connection is failing. This prevents the message from arriving.
  • The contacts on your list are out of date. This makes delivery impossible, as the emails no longer exist.

As you can see, these are just some of the many reasons why emails are bounced. And bounces are subdivided into soft, which are temporary delivery failures, and hard, which are permanent failures.

In other words, a hard bounce cannot be delivered and is therefore a very serious failure because it invalidates the message permanently.

Outdated contacts on the list are hard bounced because there is no way to deliver emails to obsolete contacts.

The same happens with temporary emails, created to last a few hours. After they expire, they become bounces because they no longer exist.

Messages that can be reversed, such as a full box, technical server failures, etc. are less serious and are therefore called soft bounces.

Now, imagine the number of risky emails on a list that wasn’t built correctly but was bought?

It’s worth remembering that bases containing only 3% of bounces are blocked.

How to calculate the bounce rate?

To arrive at this result, divide the number of rejected emails by the total number sent. Multiply the result by 100.

Measuring bounce rates is very important, as professionals can use this result to improve delivery rates, which are directly affected by the bounce rate.

How to reduce bounce rates?

  • By validating emails, you can create a schedule for cleaning and updating lists, frequently removing unengaging, temporary, obsolete emails and all types of invalid contact.
  • In the case of contact forms, install the real-time verification API, which has the function of automatically correcting emails with typing errors, as well as vetoing the entry of disposable contacts, inactive contacts and other types of invalid emails.
  • When building your list, use double opt-in. Just to remind you, opt-in is the permission the recipient gives to receive your emails. It is linked to the registration form.

With double confirmation, the user only enters your database after being authenticated, via a link that you send by email.

This way, you guarantee that the lead is really valid and is interested in accessing your communication.

  • Always monitor the delivery rate of your emails. That way, you can see the reasons that are leading to a possible drop and have time to act to reverse the situation.
  • Create a targeted incentive for inactive contacts to promote re-engagement with your company or service.


Email marketing offers numerous functionalities for anyone working in communications or sales.

As well as allowing a totally personalized approach, the ROI of US$ 42 on US$ 1 investment alone justifies its use as a lead generation and nurturing tool.

That’s why keeping track of campaign performance, monitoring lists and checking KPIs is minimal work compared to the incredible return it can generate.

Reducing bounce rates is simple. Just check your lists frequently and keep an eye on the performance of your campaigns.


How do bounces come about?

Bounces are emails that fail to be delivered for various reasons, including typos in registration forms, non-existent or obsolete emails, the recipient’s server experiencing technical problems and a host of other reasons – temporary or permanent – that prevent the message from being delivered.

What is the difference between soft bounce and hard bounce?

Soft bounces are temporary delivery failures, i.e. emails are prevented from reaching the recipient for reasons that can be reversed. For example: a full inbox, or connection failures. Hard bounces are messages that cannot be delivered for permanent reasons, i.e. there is no way of reversing the reason that prevented delivery. Emails that don’t exist or accounts that have been inactivated are some examples of hard bounces.

How to reduce the bounce rate?

Email verification is essential because it allows professionals to monitor the health of lists and remove bounces. In addition, the double opt-in option also guarantees the construction of a list containing genuine leads, and in the case of registration forms, the installation of the real-time verification API prevents the entry of risky emails.