What is a bounced email?


A bounced email is an email that doesn’t reach one or more subscribers on your email list because the recipient’s inbox provider rejects it. A high number of bounced emails reduces your email deliverability, negatively affecting the performance of your email campaigns and automated emails, or flows.

Depending on why the delivery failed, there are 2 main types of email bounces:

  1. Hard bounce: A hard bounce happens when an email can’t be delivered for a permanent reason, such as a misspelled email address or a recipient blocking your emails with a spam filter.
  2. Soft bounce: A soft bounce reflects a temporary issue on the recipient’s end, such as a down email server or a full inbox.

How to prevent bounced emails

To reduce the rate of bounced emails, try these strategies:

  • Use double opt-in: After someone signs up for your email list, send a follow-up email that requires them to confirm their subscription before they start receiving marketing messages.
  • Watch out for spammy words: Words like “cash,” “deal,” “income,” or “credit” can trigger spam filters, so avoid using them in your email copy and subject lines.
  • Sunset unengaged contacts: Keep potentially invalid email addresses off your list by regularly removing contacts who haven’t opened your emails in a certain period.

Klaviyo is a marketing automation platform that automatically suppresses any emails that have bounced more than 7x in a row, helping keep your email list fresh and relevant. 

To minimise the effect of bounced emails on your deliverability rate, Klaviyo’s deliverability hub offers a quick and easy way to monitor deliverability metrics and see what to act on, including:

  • Your account’s overall deliverability score
  • Monthly bounce rates 
  • Bounce rates for each of your campaigns
  • The reason why your emails are bouncing, arranged according to different sources

Sign up for Klavio to maximise the reach of your marketing messages, making sure your emails always find their way to your audience.