Bounce definitions

Bounce definitions
Sometimes your emails won’t get through to the recipients inbox. Fortunately our email marketing system will let you know why something has bounced.

Hard bounce vs Soft bounce
A hard bounce is an invalid email address and will be placed in the suppression list.
A soft bounce is an email address where delivery was unsuccessful but it doesn’t necessarily mean the email is invalid.

If an email address bounces too many times, it will be suppressed in your account to prevent you from sending to it. This helps to protect your sending address and server from being blocked for spamming.

The default settings are to suppress a contact after 1 hard bounce; and to remove a contact without suppression after 4 soft bounces. If your account has the feature enabled, you are able to configure this in the Contacts section of the system.

List of bounce and suppression types
At various points in the system you may see references to bounce types, they are explained below.

Globally Suppressed
Contacts who have either complained directly to us in the past or are known spamtraps

Hard bouncers
Contacts whose addresses are permanently unreachable, most likely because they, or the server they were hosted on, do not exist.

Soft bouncers
Contacts whose addresses are temporary unavailable, possibly because their mailboxes are full or their server is having temporary issues accepting mail.

ISP Complainers
Contacts who have submitted spam complaints to us via their internet service provider.

Mail blockers
Contacts who have received messages that their provider does not want to process, possibly because of attachments.

Domain Suppression
Contacts whose email domain you have previously added to your suppression list.

Soft bounce
The mail server that handles mail for this email address didn’t accept the message when we tried to send it; however, trying again later may succeed.

Soft bounce – DNS failure
Although we tried several times, we were unable to determine which mail server is configured to accept mail for this email address. This may be due to the correct mail server undergoing maintenance at the times we attempted to send the message.

Soft bounce – mailbox full
The recipient’s mailbox is too full to accept the message you tried to send them

Soft bounce – message too large
The recipient’s mail server won’t accept a message of this size

Bounce – no email address
A bounce came back, but the mail server we sent the message to didn’t indicate who the bounce was on behalf of. We’ve identified the intended recipient, based on the content of the message being returned.

General bounce
The mail server returned the message to us, but didn’t indicate a reason why.

Mail blocked
The mail server indicated that it didn’t want to receive the mail. No reason was given.

Mail blocked – known spammer
The mail server has decided that your message doesn’t satisfy their filtering criteria, and thinks it may be spam. It has been rejected.

Mail blocked – relay denied
The mail server says that although the recipient’s domain is pointed at it, it won’t currently accept mail for that domain.