Bounce Solutions

A number of your recipients have not received one of your campaigns due to it having bounced. Don't panic! It isn't the end of the world!
Whether it is a hard or soft bounce there are resolutions that can be put in place so the contact can be delivered to.

This article will cover these solutions for each of the bounce list reasons.
To read about what each bounce reason means, please read our Bounce Reasons article.

Bad Configuration

This is an issue with the recipient rather than your set up.

In this case you would contact the recipient directly and try to find a resolution for this.

Bad Connection

This is also an issue with the recipient.

Again we recommend you contact the recipient, notify them of the issue, pointing them to their internet provider initially.

Bad Domain

If you have a bad domain this is usually linked to your activity on that domain.
Spam related or malicious activity will cause your domain to be classed as "bad" and will eventually become blacklisted.

To resolve this issue you need to carefully examine your domain activity and eliminate any suspicious, malicious, or spam like activities.

Bad Mailbox

This usually occurs because the email address of the recipient no longer exists.

The quickest resolution is to determine if the email address is still relevant i.e. if the recipient is still a member of that company. If they aren't then choose another member of that company to email.

Inactive Mailbox

This is relatively simple to resolve.

Find a recipient from the same company to send to. Or ask that contact for any alternative email address to send to.

Message Expired

Previous attempts of sending an email to the recipient in this case have failed.

Your best action is to re-send when the sending queue is less saturated.

No Answer from Host

This issue requires first contacting the administrator of your server to identify any issues.

If this is not fruitful then we recommend liaising with the customer directly to solve this issue.

Protocol Errors

Again this is an issue you will need to contact the server administrator for to resolve.

Quota Issues

If someones inbox is full you will have to find an alternate email address to send to or a different contact in that company.

Routing Errors

You will have to again contact the server administrator and explain the issue, as well as with your internet provider so they can try and locate the problem.


Unfortunately there isn't much you can do in this situation apart from the generic checks.
The reason cannot be identified so it is impossible to know the cause.

Challenge Response

The email recipient has challenged whether you are a robot or not. Usually this is a simple task of confirming you are not a robot, as a lack of response causes the bounce.