Hard Bounce Vs. Soft Bounce in Email Marketing Explained
When you send emails to clients from an email marketing platform (e.g. MailChimp, Constant Contact, Zoho Campaigns, etc.), the email marketing platform will record whether or not the emails were delivered successfully to your intended recipients. If the emails did not go through successfully, the email marketing platform will be notified by the receiving email server and mark the particular message as a “bounce.”
The email marketing platform will then mark the bounce as a soft bounce or hard bounce based on the data it receives from the receiving email server.
This article describes the difference between soft and hard bounces, what triggers them, and what you can typically do to resolve the most common bounce reasons. I have based this information upon my personal experience assisting our clients with both ongoing and one-off email marketing campaigns.
Additionally, this data is extracted from my team and I’s over a decade of using multiple email marketing platforms, the most common of which we directly use is MailChimp, Zoho Campaigns, and Constant Contact. Thus, this data and how bounces are handled are partially based upon each platform’s internal polices, documentation, and technical support responses.
Keep in mind there are hundreds of email marketing platforms out there like ConvertKit, Beehiv, Aweber, etc., all of which track bounce rates and can treat them slightly differently.
Table of Contents
The Difference Between Soft and Hard Bounces
It is important to understand the difference between hard and soft bounces. In both cases, the email you sent was rejected by the recipient’s email server, yielding a “bounce” which is categorized as either a hard or soft bounce.
At a high level, soft bounces are temporary email delivery failures that may resolve, whereas hard bounces are permanent email delivery failures.
However, there are a myriad of subtypes of both hard and soft bounces which require distinct levels of attention and resolution.
What Is a Hard Bounce in Email Marketing?
A hard bounce response indicates that the reason the email was not delivered to its recipient is likely a permanent issue.
Note that many email marketing platforms will automatically remove hard bounces from your subscriber list. So, the solutions listed below for hard bounces may already be done depending on your platform. However, we still recommend checking the email addresses that hard bounced to confirm the appropriate action was taken.
List of Hard Bounce Reasons and How to Fix
The following are the most common reasons a hard bounce may occur when you send a message. We also included the typical solution for resolving hard bounces.
The Recipient Email Address Does Not Exist
If the recipient email address does not exist, it is possible that the employee is no longer at the company (or has changed email addresses), and the mailbox has been shut down. Alternatively, this could be triggered if the email address was entered incorrectly (typo) into your email marketing system.
Solution: Check the recipient email address and update it to the correct email address. If the email address is truly no longer valid, unsubscribe/remove it from your email marketing list.
The Domain Name Does Not Exist
If you receive a message that says the domain name does not exist, it means the domain name (e.g. ignitingbusiness.com) is no longer publicly registered and/or is not configured to receive mail. That means no matter what email address you use at the domain (anyone[at]ignitingbusiness[dot]com), the email will not deliver.
This usually indicates a typo in the domain, the domain name expired, or the company may be shutdown altogether.
Solution: Check the recipient email address and update it to the correct email address. If the email address is truly no longer valid, unsubscribe/remove it from your email marketing list.
Note that some email marketing platforms (including MailChimp) treat this issue as a soft bounce instead.
The Recipient Email Server Has Blocked Delivery
This usually only occurs if your sending domain name has been blocked by the receiving email server’s domain name, or perhaps your domain name is listed on a public email blacklist for malicious or suspicious behavior.
Solution: Double check your domain against common email blacklists and resolve any issues as indicated by the blacklist’s resolution steps. If your domain is not on any blacklists, you may want to contact the recipient’s IT department to see if you can get your domain name removed from their internal blacklist/quarantine.
What Is a Soft Bounce in Email Marketing?
A soft bounce usually indicates a temporary issue where the email did not deliver to its intended recipient; soft bounces can sometimes self-resolve.
In fact, email marketing platforms typically allow you to resend emails to email accounts that soft bounce a select number of times before it automatically cleans (removes) them from your list.
When Should I Troubleshoot a Soft Bounce?
Please keep in mind that soft-bounces often self-resolve since they are “temporary” issues, so it may not be worth spending time on this if a particular user soft bounces only once. However, if you see a high percentage of soft bounces or the same user bounces multiple times in a row, this should be a sign to investigate further.
The soft bounce reason might impact the level of effort you put into troubleshooting.
List of Soft Bounce Reasons and How to Fix
Since soft bounces commonly occur due to a myriad of issues, many of which may not require a resolution, I made a quick table to show the most common types of bounces and how they should be addressed.
To make life easier, I have split these soft bounces into issues that you (and your email marketing platform or IT team) would likely need to resolve vs. your customer’s email service provider/IT team would need to address.
What Happens When You Keep Getting Hard or Soft Bounces?
If you continue to keep getting hard or soft bounces, most email marketing platforms will attempt to automatically “clean” your lists which removes your ability to send emails to the bounced contact. They do this to maintain the “sender’s reputation,” which keeps your ability to deliver emails to other recipients.
In full transparency, automatically cleaning bounces also protects their email platform from being one that is classified as sending spam emails. So, while they do some of the work for you, it is also slightly self-serving, and automated for the sake of scalability.
Each email marketing platform is different in how many soft/hard bounces it will allow before cleaning the contact. The following are the three email marketing platforms we have the most experience using over the past decade plus of offering email marketing services.
How MailChimp Addresses Hard and Soft Bounces
Typically, hard bounces will be cleaned from your email list immediately. MailChimp will allow 7 soft bounces if the subscriber has no activity with your campaigns, and up to 15 soft bounces if the subscriber had previous activity. After it hits the quota, MailChimp will convert the soft bounce to a hard bounce and remove it from your list.
MailChimp also has a policy that if your account continues to get high bounce rates above “industry thresholds,” your account may be suspended.
How Zoho Campaigns Addresses Hard and Soft Bounces
Hard bounces will be cleaned from your email list immediately. If any email address typically reaches 7 soft bounces, it will be re-categorized as a hard bounce and no longer receive mail.
If your bounce rate exceeds 5% for a specific email campaign, Zoho Campaigns will temporarily pause sending the campaign and notify you. If it continues to exceed 5%, they may permanently cancel the campaign, and your account could come under further scrutiny.
How Constant Contact Addresses Soft and Hard Bounces
Constant Contact chooses to manage soft and hard bounces somewhat differently than its competitors, for better or worse. It still tracks soft and hard bounces, but uniquely tags these contacts and provides separate action steps. We could write a whole blog post on how this process works, but instead, we highly recommend you read Constant Contact’s approach directly from their knowledge base.
Review Your Bounce Rates Regularly and Keep Them Low
It is critically important that you review your soft and hard bounces regularly to identify any issues that may be impacting your email deliverability. If you’d like more tips regarding email marketing tactics or other online marketing topics, subscribe to our free monthly newsletter.
