What is an email bounce?

Not all emails can be delivered, when they fail a so called "email bounce" is triggered. Why does that happen and what kind of email bounces are there?

What are email bounces?

Everyone has probably sent an email to someone at some point that failed to deliver. In such cases we receive a bounce notification, that informs us about a failed delivery and the reason for the bounce.

Especially in business contexts email bounces are undesirably, as you are trying to reach partners or customers in a one-on-one conversation or via promotional marketing campaigns.

But an email bounce does not only mean your conversation partner won't get your message, if too many email bounce it can also effect your so called "sender reputation", which may lead to even more emails being rejected and bounce in the future.

What is an email bounce?

An email bounce is simply an event that happens when an email can not be delivered, for whatever reason. While a failed email delivery can have multiple reasons they usually all result in a bounce notification, following the RFC 6522 specification from January 2012 or earlier versions.

Such a bounce notification in itself is simply another email informing you that the email you sent could not be delivered. It usually consist out of a text part that is readable and details for the receiver what happened, and a machine part with a log file of the error trace.

What kind of bounces are there?

Generally a distinction is being made between soft and hard bounce emails. A soft bounce is often indicating a temporary problem, like unavailability of the recipient server or a full mail inbox. Depending on your email service a soft bounced email may continue to attempt a delivery for a couple of hours, until it succeeds or results in a hard bounce.

On the other hand a hard bounce is a permanently failed delivery that can occur for a multitude of reasons. Most commonly when sending emails to an invalid or misspelled address, a spam block or a suppressed sender identity can cause a permanently failed delivery.

How can I avoid an email bounce?

Avoiding email bounces is paramount in every business that relies on digital communication. When corresponding about business details, promotions or similar content you want your partners to be able to receive your messages without bock or delays.

There are a few factors you can influence on your side to make that happen, for example it is advisable to always have up-to date contact informations of your contacts. You can only reach them if you know their email address. Common mistakes include a misspelled name, domain name or top level domain (e.g. "con" instead of "com").

Another important aspect is your sender reputation, if your website is known for spamming or sending fraudulent emails your communication is much more likely to be blocked by other email providers. The same goes for situations where you are in a so called "bad neighbourhood", that refers to your emails being sent from servers or IP addresses associated with third-parties that are bad actors.

Sending and managing emails, especially in a promotional context, is integral to successful businesses. Managing your digital communication and channels is not always straight forward and often requires expert assistance. Talk to our email gurus by filling out the form below or sending an email to!

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