Managing bounces for better deliverability

A bounced email is one that does not arrive in a recipient’s inbox – instead, an error message is returned to the sender, usually with an error code and a reason why the email wasn’t delivered. Campaign Master processes these bounce messages, makes them available for statistics and reporting and uses them to execute automatic bounce rules.

There are many different reasons an email might bounce. These can generally be divided into two categories – hard and soft. A hard bounce usually occurs because of an incorrect email address (e.g., the domain doesn’t exist or the user at that domain doesn’t exist), or due to a network failure or blocking by the ISP (Internet Service Provider). A soft bounce indicates that, while the email address is valid, the email wasn’t delivered due to mail server failure, a full inbox, or large volumes of email traffic.

In addition to the above, ISPs are increasingly using bounces to reject emails they have identified as spam, or because of other poor sending practices. An ISP will use a number of factors to assess incoming email, such as the external reputation of the sender’s IP address or domain and how many complaints (i.e. users reporting emails as spam) have been made, the design and content of the email, the number of unknown users being sent to and whether the sender is on a blacklist or whitelist. Continuing to send emails to a recipient that bounces will affect your reputation both with that ISP and externally.

It is essential that you have effective bounce rules set up to automatically handle soft and hard bounces when you send a campaign. There isn’t one definitive way to set up these rules – they should be tailored according to a number of factors, such as sending frequency, the type of recipients you are sending to (e.g., work or personal addresses), the design and content of your email and the cleanliness of your database (e.g., are your recipients confirmed subscribers or did they come from a purchased list?).

As an example, you might set up a rule to run whenever you receive a single hard bounce from a recipient, and another rule to run when you receive three soft bounces from a recipient over the course of five consecutive campaigns. These rules should make the recipient inactive, so no further campaigns will be sent to that recipient until they are reactivated.

As well as having automatic bounce rules in place, it is important to do your own monitoring of bounces and the reasons for them – from this you may be able to identify a problem sending to a particular ISP, or that some of your campaigns are more likely to bounce than others, or that recipients’ email addresses are incorrect. You do not want to remove valid recipients from your database, but you may want to change the type or frequency of campaigns that you send to them.

What can you do to minimise and handle bounces?

• Set up bounce rules correctly and check that they are effective
• Monitor all bounces you receive and actively manage bounced recipients
• Modify the content and/or design of your campaigns and change your sending behaviour, to conform to best practice standards
• Clean your database by removing incorrect email addresses or nonexistent domains, or removing other recipients that you know should not be receiving emails.
• Use a double opt-in subscription process to ensure that all recipients being added to the database are genuine
• If you are using a shared IP address, obtain your own sub domain and IP address – this allows you to monitor and manage your own reputation
• Encourage your recipients to add your email address or domain to their safe senders list. Download our step-by-step guide here.

For more information on managing bounces, contact us today.