Soft Email Bounces Explained - Fundamental Marketing

Soft Email Bounces Explained

Feb 04

What is a Soft Email Bounce?  

Regardless of the email platform you are using (Keap, Infusionsoft by Keap, Ontraport, Hubspot Active Campaign etc) bouncing emails (an email that never actually got to your intended recipient) are an unavoidable part of the life of anyone using email to market their business.

Bouncing Email

High bounce rates (more than 2%) create negative impacts that you must be aware of:

  • Bad reputation. ISP's monitor and watch for addresses that continue to send messages to invalid users.  
  • Low Inbox placement.  ISP's monitor bounce rates for every campaign you send, and use that information to decide where to delivery your emails in the future (the inbox, promotions folder or junk folder).
  • Blacklisting. Frequently seen high bounce rates get the sender's IP address land on blacklists supported by ISPs and anti-spam organizations.
  • Account suspension. Email service providers (Keap, Infusionsoft by Keap, Ontraport, Active Campaign or Hubspot) have a strict policy as to how they internally handle bounce and complaint rates. They will suspend the user's account if the campaign sent by the user generates a complaint rate that is beyond the ESP's allowed limit.
  • Lost revenues. Email service providers charge you for each message you are sending or store within their systems. Invalid email addresses are increasing the cost of your email campaigns without any return on investment.  Furthermore, poor inbox placement will have a negative impact on your email marketing campaigns.

But what are these different types of bounces and what do they mean?  

Well luckily for all of us, bounces are not as mythical as Unicorns and they can be dealt with once you understand what they are and why they are occuring.

The first item to realize is that there are two types of email bounces, soft bounces and Hard Bounces.  A hard bounce occurs when the message has been permanently rejected.  A soft bounce means that the email address was valid and the email message reached the recipient’s mail server but was not accepted at this time.  

Hard Bounces

A hard bounce is an e-mail message that has been returned to the sender because the recipient's address is invalid. A hard bounce might occur because the domain name doesn't exist or because the recipient is unknown, the domain name does not exist or the recipients mail servers are completely blocking delivery.  Hard Bounces are automatically handled by most ESP's (like Keap or Infusionsoft by Keap).

Even though hard bounces are automatically handled once they occur, you want to be doing everything you can to minimize these hard bounces from occurring as they Will HAVE A NEGATIVE IMPACT ON YOUR INBOX PLACEMENT.  Good list hygiene practices (regularly cleaning your list with a third party tool and engagement tracking) is highly recommended to prevent these email toxins from staying in your list and hurting your deliverability.

Soft Bounces

When talking about soft bounces,  we are talking about is a temporary bounce.  A bounce that can be classified as temporary indicates that while the delivery of this current message was unsuccessful, you may be able to deliver another email to that address at a later date.   If an email gets a soft bounce on an email send, most email providers will attempt to deliver the email over the period of a few days (this is why an email may show bounced and opened). You should keep an eye on these addresses -- if you notice that the same ones are popping up over and over again, it's best to remove them.

Bounce Rates should be kept under 2%.  Any higher than that and you will likely see a negative impact on deliverability

To help you understand soft bounces better and what this all means, here is a list of the soft bounce types and their meaning:

  • Mailbox Full: The recipient's email box is too full. There is no room for the message. Most of the time this is related to improper maintenance, but it could mean that the recipient no longer actively uses the email account even though it still exists.
  • Message too Large: There is content in the message or attachments causing the message size to exceed the limits of the receiving server.
  • DNS Failure: The email cannot be delivered due to an issue with the receiving server. This is most likely an issue with the nameserver settings for your domain. Contact your domain administrator for assistance. The issue may be related to the SPF records.
  • General: The specific reason for the bounce has not been detected.
  • Auto Reply: This kind of soft bounce indicates the message has been delivered, but the recipient has an auto-reply enabled on their account. The bounce status will be removed as soon as the recipient opens the email.
  • Subscribe Request: These are recorded when an auto-reply is sent to your bounce capture email account ([email protected] or [email protected]) asking to be added to your list. They are a type of soft bounce since most people would not send a message to these accounts.
  • Mail Blocks: A mail block is recorded when the recipient's email server blocks an email message completely. It rejects it before it tries to deliver it to their inbox.
  • General: The recipient's email server is blocking messages sent through the Infusionsoft server.
  • Known Spammer: The recipient's email server is blocking messages from your email account based on an email history or reputation that indicates you've been sending SPAM.
  • Relay Denied: The recipient's email server is blocking messages sent through the Infusionsoft server. Setting up your SPF to include will help you resolve this issue.
  • Spam Detected: The recipient's email server is blocking your email because the content looks like SPAM. Use the Infusionsoft Spam Score tool in the email template to check the email content and reduce the SPAM score below 5 (preferably zero.)
  • Attachment Detected: The recipient's email server is blocking the message because of the attachment. It may have identified the attachment as a possible virus source, the system may not allow attachments at all, or may block specific types of files (e.g. .exe). The size of the attachment may also be causing an issue. Make sure your attachment size is less than 10 MB.
  • Unsubscribe Request: These are recorded when an auto-reply request is sent to your bounce capture email account([email protected] or [email protected]) asking to be removed from your email list. A real person will reply to the email or click on the Unsubscribe Link.  These Unsubscribe Requests are the same as an ISP Spam complaint.
  • Undetermined: An undetermined status is assigned when Infusionsoft is not able to identify the cause of the bounce based on the feedback received from the receiving server.

Here are a few tips that will help you reduce your bounces and be in good standing with the email Gods.

  1.  Do not buy, rent or harvest email addresses.
  2.  Use a confirmed (double) opt-in process
  3.  Regularly clean your list 
  4.  Monitor Bounces by domain.
  5.  Remove emails that are repeatedly soft bouncing.
  6.  Test your emails for Spam Score before you send.
  7.  Setup proper email infrastructure (SPF, DKIM, DMARC)

Email bounces will happen, the key thing you must remember is how they impact your domain’s reputation>   A little bit of planning and prevention will go a long way towards protecting your domain’s reputation and help you to increase your odds of landing in the inbox of your subscribers.


About the Author

Evan Samurin is a third generation entrepreneur with a passion for helping business move from transactional to transformational. Having worked with entrepreneurs over the last 9 years, Evan is a wealth of knowledge. Evan leverages passion, compassion and wit to help entrepreneurs thrive.