Email bounce is when an email is not delivered because it has been rejected outright by the receiving email server.
In the case of ‘hard’ bounces this may be because the email address does not exist, or it includes a typo, an unsupported character, or is missing part of the address. Hard bounces are permanent and will never be resolved unless the email address is updated.
A ‘soft’ bounce on the other hand is a temporary rejection. In this case the email address is valid, but the recipients’ inbox may be full or there may be a technical fault with their email service provider. If you resend the email after a period of time, then it is likely that it will be successfully delivered once the fault has been resolved.
Some email service providers will treat a soft bounce as a hard bounce if the message fails to send three times in a specified period.
What happens if emails bounce?
Apart from the message not getting delivered and recipients potentially missing out on important information, with a large number of hard bounces over time your sender reputation will be negatively affected. This could see your messages end up in recipients’ spam folders or could even get you blacklisted by email service providers.
How to avoid email bounces?
Good quality email data will ensure that email bounces are kept to a minimum.
To ensure this from the start you should get subscribers to confirm their address in a two-step process to ensure they don’t make any typos. You can then send the final confirmation to the provided email address to ensure that the email account is theirs.
If you have a quality issue with your existing email data then you can get it validated, in other words a vendor will confirm that each address in the list is valid. Infobip provides an email validation service.
How to measure email bounce?
The email bounce rate for a deployment is the number of bounced emails divided by the total number of recipients in the deployment. By industry standards, if the bounce rate for your deployments is more than about 2% then you should take action to improve the quality of your email lists.
