About Bounces

Bounces occur when an email can't be delivered to an email address. When an email bounces, Mailchimp classifies it as either a soft or a hard bounce.

In this article, you'll learn about the types of bounces, guidelines for bounce limits, and how to handle them.

Types of bounces

Mailchimp recognizes two types of bounces, and we handle them differently.

• Hard bounces
  Hard bounces happen when an email can't be delivered. This can be caused by an invalid email address or an unexpected error during sending.
• Soft bounces
  Soft bounces are recognized by the email server, but are returned to the sender for a variety of reasons. This can include issues like the mailbox being full or temporarily unavailable.

To learn more about the two types of bounces, check out this guide.

Soft vs. Hard Bounces

High bounce rates

High bounce rates are often caused by audiences that have gone stale, or addresses that were improperly entered or imported.

Internet service providers (ISPs) have limits for bounces, unsubscribes, and abuse complaints, and Mailchimp is required to enforce these limits. If these rates are too high, it could prompt a warning or suspension on your account.

Bounce rate limits vary between ISPs and email providers, and they change throughout the year based on incoming email volume. Because these limits are variable, and to avoid giving too much information to spammers, ISPs do not publicly release their limits.

How to avoid bounces

If you haven't sent an email in a while, reconfirm your audience to keep your contact information up to date. This should help protect your audience from spambots and fake signups that lead to bounces.

About Bounce Warnings
Reconfirm Addresses

Does Mailchimp manage bounces?

Yes. After you send an email with Mailchimp, we track its delivery and clean bounced addresses from your audience. Emails won't be sent to those addresses anymore, but you'll still be able to access them if you need to.

Sometimes hard bounces happen to valid email addresses. If a bounced address has recently engaged with your emails, we won't remove it from your audience right away. The bounce will be noted in the contact's profile and count toward their contact rating as we keep an eye on future activity.

Requirements and Best Practices for Audiences
About Contact Ratings

About contact cleaning services

Although we manage bounced addresses for maintenance purposes, Mailchimp is not a contact cleaning service. If you import old or invalid contacts, addresses which bounced or unsubscribed previously could lead to a high number of spam complaints, undeliverable messages, or unsubscribes. To avoid these problems, follow best practices when adding or importing subscribers to your audience.

About List Cleaning Services