Bounce Rate Cheat Sheet

What Is An Email Bounce?

Email bounce (or “bounce”) is an error message received when the email you’ve sent isn’t delivered. Your email server or the destination (recipients) mail server sends this NDR (Non-Delivery Report). The bounce message also lets you know the delivery failure reason of your email. In SmartReach, you will find the bounce emails and their reason here. (next line, show the path to go to the bounce email list)

What Is A Bounce Rate?

"Bounced" denotes the number of prospects to whom the email failed to deliver and "Bounce rate" denotes the ratio of Bounced to the total number of prospects contacted. The lower the rate the better.

What Causes An Email To Bounce?

Bounces can be in 2 categories:

1) Soft Bounce occurs when email deliverability fails temporarily.

2) Hard Bounce occurs in a situation where the emails cannot be delivered permanently.


Let’s discuss each category in detail.

There are several reasons for an email to soft bounce.

  • Lack of space in the inbox or mail server
  • Unreachable destination
  • The server may be down or overloaded
  • The email size may be too large
  • Server blocking due to poor reputation
  • The sender’s server is being blocklisted
  • Recipient using auto-responder

The reasons for a hard bounce are

  • Email id may be incorrect
  • Failed email validation
  • Email account suspended
  • Email address blocked
  • Blocking of external emails by organizations with strict security policies
  • Policy filtering set by the recipient
  • The server may not exist

How To Reduce The Bounce Rate Within The SmartReach App Environment?

While it's impossible to completely eliminate bounces, some practices can be followed to lower the bounce rate. The rising bounce rate is a clear indicator that there is an issue with email deliverability. It's important to understand that multiple factors affect bounce, so you can't address only one point and expect a change in the bounce rate.

Some tips on how to reduce the bounce rate within the SmartReach app environment:

  • Check your SPF and DKIM status in our SPAM Test Report
  • If SPF is missing or blanks for Office365 (Click Here)
  • If SPF is missing or blanks for Google Workspace (G-Suite) (Click Here)
  • Campaign Content - Avoid using keywords that could trigger spam filters. This document contains a list of commonly used keywords and phrases that possibly trigger spam filters
  • Send a max of 150 emails/day per sending email address. If the number of emails sent increases then the chances of getting blocked by the email service provider also increase.
  • Maintaining a time frame between 2 consecutive mails
  • Always start a campaign with the “Campaign Soft-Start” feature. This incrementally increases your daily sending of emails. The gradual ramp-up ensures higher email deliverability
  • Our free email validation feature automatically blocks the sending of emails that are not verified. Do not force push blocked email IDs unless absolutely sure that the email is valid.
  • Best practices for writing effective cold email campaigns have been covered in this document.

Other External Factors That Reduces Bounce Rates

Below are some external factors that would help reduce bounce.

  • Cleaning the Email List - Over time, the email list may get populated with inactive & hard bounced ids. It is a best practice to clean the list and keep it active and healthy.
  • If you witness a lot of email bounces from a specific domain. Make a note and ensure that you eliminate email from this domain during your email list clean up
  • Content should not be spammy - Too big or too small images should not be used.
  • Proper segmentation of the Email List - Imagine sending a proposal for accounting software to the “Head of Content”. Improper segmentation increases the chance of being marked as spam
  • Double Opt-In - This ensures that inactive or invalid email ids will not be added to your email list.
  • Use verified domain - Email ids of the verified business domain should be used instead of free email service providers.
  • Be consistent - Send regular emails to your subscribers rather than sending all the information out altogether.
  • Engaging content should be sent every time.
  • Avoid buying an email list. If done then please ensure that you run it through an email validation software.
  • Company-owned email domains or business domains should be used
  • Keeping an eye on the sender’s reputation score