Bounces & NDR

Undeliverable mail with a plain explanation of the reason and a concrete recommendation.

Bounces & NDR collects every mail that could not be delivered and translates the cryptic error messages of the receiving servers into plain explanations with a recommendation.

Permanent or temporary

• Permanent (e.g. "mailbox does not exist"): correct the address or take it off your list. Repeated attempts at dead addresses damage the standing of your domain.
• Temporary (e.g. "mailbox full", "try again later"): the server keeps retrying by itself, and there is usually nothing for you to do.

Reading the explanation

Every entry shows the original response of the receiving server next to an explanation of what the error code means and what to do about it. Common cases: a typo in the address, a full mailbox, rejection as suspected spam (then the DNS records are worth a look) or a blocklist at the recipient's end.

Keeping an eye on the bounce rate

Today's bounce rate is on the dashboard, as are the most common bounce reasons of the last 7 days; the 30-day trend is under Statistics. A permanently high bounce rate is the most important warning sign of an ageing address list, and you can have a warning sent to you once it passes a threshold you choose (see Notifications).

Addresses that are permanently unreachable are collected by the blocklist. It outlives the 30 days of the logs and is the list you take over into your own system.

You will find this feature in the customer portal: my.mailbridge.email, included in every plan.

No account yet? Try it free for 14 days, payment details are only needed afterwards.

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