A list's complaints, bounces, and unsubscribes indicate its overall health and quality. They represent not only how satisfied your subscribers are with receiving your emails, but also how they feel about your entire email marketing strategy. Each of these factors affects your list differently, so we'll cover them individually.
Why this is important
A person unsubscribes from a list when they no longer find the emails sent relevant and they will most likely flag it as spam if they continue to receive the emails after unsubscribing. Thus, if a list of people who are waiting to open the email is regularly sent engaging and/or timely content, the unsubscribe rate should be zero (or very close to it). For these reasons, understanding the following terms is essential to monitoring and maintaining a list's health:
A “hard” bounce
This happens when an address no longer exists (or might have never existed). These situations can have dramatic consequences for your account, sometimes even resulting in suspension, all hard bounces will be removed from the list as a result. If the address never existed, you can avoid this by simply sending a subscription confirmation email.
A “soft” bounce
Due to a "temporary" problem, the email is currently unavailable. An email address will be automatically removed from the list if there are four soft bounces on it. It is important to note that your reports provide you with very detailed information about bounces on your emails, including several types of bounces not listed here.
These emails are therefore removed in order to avoid SPAM complaints. Additionally, it will help with future email statistics.
The bounce rate is calculated as follows:
Total bounces / Total number of people you sent your email to
There should be no more than 1% hard bounces. Furthermore, your bounce rate may be influenced by the following factors:
- Industry type
- Is your list up-to-date?
- What is the frequency of your mailings? Each campaign's rate falls as you send more frequently.
The unsubscribe rate is calculated as a percentage of:
Total number of unsubscribes / Total number of people email was sent to
Always remember that unsubscribing is better than flagging you as spam. To add an unsubscribe link to your email, refer to our guide on how to do so.
The spam complaints rate is calculated as follows:
Total number of complaints / Total number of emails sent to specific internet service providers
As soon as someone marks you as spam, they are definitively removed from the list.
0% – 0.1 %
- Use best practices to avoid complaints and send a test to yourself (see where it lands) before sending out your campaign. Should never exceed 0.25% (1 out of 400 emails sent)
Keep in mind that ISPs look at these numbers too. If you have consistently mid to critical bounce/spam levels it is only a matter of time before your emails get sent to a recipient’s junk folder and/or get blocked permanently.