Bounces

When an email can't be delivered, it 'bounces'. This could be because of:

  • A hard bounce - a mail server (yours or the recipient’s) responds saying the mailbox is unavailable. The four hard bounces reported are:

    • Invalid Domain: domain sent to is invalid, e.g. because of a typographical error (gnail.com instead of gmail.com).

    • Invalid User: local part of address doesn't exist.

    • Other Bounce: undetermined bounce.

    • Over Quota: mailbox full.

  • A soft bounce - a temporary situation that prevents delivery. These fall under six categories:

    • Inbox: a response directly to the email.

    • Flame: a response which contains profanity.

    • Blocked: receiving mail server flagged the email as spam.

    • Out of Office: automatic Out of Office reply.

    • Address Change: response notifying of address change.

    • Temporary Notice: general temporary notice reply.

The Adestra known bounce system helps manage your bounces by:

  • Recognising previously bounced email addresses.

  • Recording your bounce totals in the campaign report summary.

  • Automatically adding known bounces to a mailing suppression list prior to sending a campaign.

Note: soft bounces are filtered by our system to ensure they are categorised correctly.

Identifying a known bounce

Adestra categorises a known bounce as an email address that:

  • Receives three or more hard bounces in a 15 day period,

  • Has no soft bounces between hard bounces, and,

  • Has no successful deliveries between hard bounces.

If a successful delivery occurs, the 15 day period restarts with the next hard bounce.

Note: known bounces are identified using hard bounces from across the platform.

If you add an email address identified as a known bounce by another Adestra customer, it will be suppressed, even if you have not received a hard bounce for that address.

Since Adestra does not attempt to send to a known bounce you will not be charged for emails directed to a previously bounced address.

Note: You cannot bypass the known bounce system.

Although it is uncommon, if you think there is an email address that should not be a known bounce, contact support.

Caution: Our tests have shown that although you may gain a few extra addresses for a large list, you will also lower your overall deliverability by reenabling a known bounce as dead email addresses are sometimes reused as a spam trap to catch badly managed lists.

Managing your bounces

Suppressing known bounces is important because:

  • Many mail receivers, e.g. Gmail, Yahoo, etc., check the bounce rate as part of their sender reputation systems.

  • A high number of bounces indicates bad list management practices.

  • Bad list management lowers your reputation and increases the chances of emails being blocked or junked.

  • Some receivers use old and abandoned email addresses and use them as a spam trap.

  • Campaigns that attempt delivery to a spam trap can be penalised severely by spam filter systems.

  • A campaign that suppresses known bounces will improve its bounce rate, avoid spam traps, and protect the reputation of the sender.

Tip: you can also manually remove bounced addresses instead of waiting for them to be flagged as known bounces.

Reporting on bounces

Within the campaign report summary you will see:

  • Not attempted - the number of recipients that Adestra did not send to, which includes email addresses that have previously bounced.

    Tip: you can see the exact total of previously bounced using the 'detail...' link.

  • Bounced - the number of recipients who did not receive the attempted send, i.e. Adestra received an error message from the recipients' mail server.

    Tip: use the inbound report to view a breakdown of error messages received in relation to your campaign.

Removing bounces

Although the known bounce system will suppress risky email addresses, it is good practice to update or remove contacts that regularly bounce but do not meet the 15 day period for a known bounce using the data viewer.