Bounces, the email marketeers worst nightmare. A bounced email is an unsuccessful email that was been returned to the sender.

Most email marketeers don’t fully understand different types of email bounces and what causes them. Throughout this article we will aim to cover the different types of bounces, what causes them and how to lower your bounce rate.

So what is a high bounce rate and when should you be concerned? Email marketeers with a clean database, sending a quality email should receive no more than a few percentage points of bounced or rejected messages. If your bounce rate is a bit on the high side, don’t worry – there are plenty of actions you can take to lower it.

Before we cover how to lower your bounce rate, it is crucial to gain an understanding of the different types of email bounces and what these mean. There are two types of an email bounce; soft and hard.

Hard bounces

Hard bounces are a little easier to understand compared to a soft bounce.

Tech Target define a hard bounce an a “email that has been returned to the sender because the address is invalid”.

This definition we would argue is a little linear, there are several other reasons why a hard bounce would occur;

> Typo in email address

This is the most common reason why a hard bounce is caused. There may be a typo in the email address which is causing it to fail sending. We are human after-all, and it is very easy to make a typo. One of the most common typo’s which we find is that a user has entered their web address instead of an email contact.

We have even seen before someone entering a postal address inside their database! While most email marketing systems are pretty advanced – they have not yet got to the point where they can print off and post a letter on your behalf!

> Blocked your IP

A hard bounce may also be reported if your IP address has been blocked on the recipients server or network. If this has happened, you may wish to run a blacklist check on your email server IP and re-consider what you are sending!

> The recipients email server is down

Most web hosts will offer near 100% uptime. However if the email server which you are trying to send to is offline – this will be classed as a hard bounce.

The email server which you are trying to contact may have crashed, have a hardware fault or even no longer exist. If this is the case, your email gateway will give-up trying to dispatch the message – returning it to you as a hard bounce.

> Domain name no longer exists

A hard bounce may also occur if the domain name which you are trying to contact is no longer registered or exists.

The domain name is the part of the address after the @ symbol. If you are emailing bob@bobsmith.com, bobsmith.com would be the domain name.

When you setup a website, you will purchase a domain name. When purchasing a domain name, you will normally buy it for a set period of time. Most domain registrars will register your domain for either one or two years. If at the end of this period, the domain owner forgets to re-new the domain or no longer wants it – the address will expire. An expired domain name will cause a hard bounce.

Soft Bounce

The second type of bounce and sometimes a little harder to understand is the hated soft bounce.

AWeber define a soft bounce as the following “the email is bounced back due to a temporary issue..typically this is a temporary issue that needs to be resolved at the recipient server or the mailbox is full’.

This definition provides a brief insight into what exactly a soft bounce is – however again we would suggest that this description is a little vague and needs to be expanded on further.

AWeber are correct, a soft bounce is normally a temporary issue, this is why most email servers will try again later if your email is originally detected as a soft bounce.

So what are the reasons why a soft bounce will occur?

> Auto Reply

If the email address which you are trying to contact has an auto reply set, this will register as a soft bounce.

As the name suggests, an auto reply is a message that is sent back to you after contacting a certain address. Many large companies set auto replies if you contact their support email address. Support severs normally email you back to say – ‘thanks for contacting us, we will be in touch soon’.

If this happens, even though your email was successfully delivered, email marketing software will still class it as a soft bounce.

> Out of office

This is one of the most common reasons for a soft bounce, like an auto reply – your email has been successfully delivered but an automated response has been received.

The person who you are trying to contact may be away sunning themselves on some Mediterranean beach. As a result they set an out of office reply to remind you that you are stuck in your office while they are away enjoying the sun!

> Inbox is full

Some people are hoarders and never clean our their email inbox. Over a few years their inbox may become full and as a result the recipient email server may no longer accept incoming mail.

If the inbox is full, your email will be returned – classed as a soft bounce.

> Email no longer exists

If the email address which you are trying to contact no longer exists, this may also be classed as a soft bounce instead of a hard bounce.

In the case of a soft bounce email no longer exists return, your message successfully found the recipients email server. If for example, you are trying to contact bobsmith@hotmail.com. Your email successfully found the hotmail.com email server, but hotmail may reply that bob’s email account is no longer active. The email will then be returned to you and classed as a soft bounce.

> Spam

When your email arrives at the recipients email server, their server will scan your message and give it a spam rating. If the recipient server decides that your message does not contain any valued content it may be marked as spam and returned to you.

How can i lower my bounce rate?

Now we have covered the two main types of bounces, it is important to investigate how you can lower the percentage of emails bounced within your next campaign

> Keep it clean

Keep your email database up-to-date and clean. Over time as people switch email and internet providers a certain percentage of your email contacts will become invalid. It is important to keep your database clean and remove all dud addresses. Most recipient email servers will quickly get annoyed if you keep sending to an address which no longer exists.

All good email marketing platforms should automatically remove your hard and soft bounces. This automated clean-up will help establish a clean list. In the case of Email Blaster UK, the software will remove hard bounces once a week and a soft bounce after it has occurred more than 3 times.

> Don’t buy email lists

Build your own email database through quality double-opt in subscribers. If you purchase an email list, you will not know how up-to-date it is, have these email addresses been harvested illegally? We find that purchased list bounce rates are over double that of a quality self generated list.

> Double opt-in

Add a double opt-in email newsletter signup form to your website. Double opt-in systems will drastically reduce bounce rates compared to single opt-in systems.

When using a double opt-in newsletter signup form on your website, after the visitor applies to join your email newsletter – they will be emailed asking to confirm the subscription.

This method will ensure that the visitor is giving you a real email address and an email address which they actually own.

> Use a spam checker before sending

As previously mentioned, a bounce may be recorded if your email is considered spam. Before broadcasting your email campaign – use a spam checker to analyse and score your campaign before broadcast. This will alert you before running a broadcast if your email is likely to be considered as spam. Most good email marketing systems will offer a spam checker.