If you use Salesforce Pardot or Marketing Cloud, you may be familiar with email bounces. We certainly hope that all of your emails end up in the inbox of the intended recipient, but sometimes they just don’t. They “bounce” as the term goes, meaning a notification goes back to the sender to let them know the email did not reach the recipient. Bounces are different than SPAM filtering (which we will cover in a separate post).

The different types of email bounces

Emails bounce for many reasons. They don’t all mean the email address is not valid. Many are just common hiccups to delivery. That’s why both Marketing Cloud and Pardot will attempt to send emails to the recipient’s multiple times. With that knowledge, there are generally 2 categories of email bounces:

Hard Bounces

Hard bounces are typically thought of as permanent failures. Most often, hard bounces are caused by…

• Bad email address – For example, if you set up a customer journey in marketing cloud (or a campaign in Pardot) that grabs a visitor’s email from a landing page conversion and the email entered was misspelled. It could be the person no longer possesses the email and there is no forwarding enabled. It could be that you simply have bad data. There are many reasons why you might have an incorrect email.
• Bad domain – For example, if the entire domain (i.e. @yourco.com) is no longer being used or valid. This would wipe out anyone with that domain.

Hard bounced emails will be marked as “Do Not Email” in Pardot and Marketing Cloud and no emails will be sent in the future. You should always try to manually purge your emails or update them in the system if for example, they are a bad email address.

Soft Bounces

Soft bounces are more often temporary issues that will correct themselves in time. They include:

• Responders – Many people set up autoresponder emails that go out to let people know they are out of the office for vacations, etc.
• Temporary issues – Things like when a mailbox is full or otherwise having trouble connecting to the box.
• Block bounced – Beyond just out of office and temporary issues, your emails can be blocked for a few more reasons. It could be you haven’t configured the Sender Policy Framework (SPF) records incorrectly, or the IP address of the server you are sending it with is blacklisted. It could be your content as well (inappropriate language or imagery tripping filters) or even links from content that seem suspect or if the total email size is too big (attachments can cause issues).

When soft bounces are detected, Pardot & Marketing Cloud will attempt to resend them up to 5 times at intervals in between that hopefully sees them get into the inbox eventually. After those five attempts, they will be marked as “Do Not Email” and no emails will be sent in the future.

Bounce Rate Defined

A bounce rate is the percentage score of your total hard and soft bounces as a percentage of your total email sent. For example, if you send 1,000 emails and you get 55 hard bounces and 28 soft bounces, you would divide the total of hard/soft bounces by the total number of emails times 100 (55+28=83/1000=.083 times 100 = 8.3%). So you would have an 8.3% bounce rate. Congratulations! Anything under 10% is pretty good as an industry standard.

Parting thoughts

Even in 2019, email, whether in bulk or one-to-one is still one of the most effective and measurable methods of marketing across the board. Delivery matters and why messages are not delivered becomes an important topic to help you hone your efforts. We recommend paying attention to your bounce rates, percentages and the reasoning to make your campaigns more successful.