Hard Bounces, Soft Bounces, and Suppressions

  • Updated

When you send an Act-On email message it may not be successfully delivered to the end recipient. These are known as soft or hard-bounced messages.

When Act-On attempts to deliver an email message, our email server communicates with the recipient's email server. The recipient's server may inform us that it cannot accept the message, and it will provide a reason. This reason called a bounce code, is then displayed in Act-On in your message reports – these can be very helpful for finding trends in your bounced messages.

Hard Bounce

A hard bounce means that the email is invalid or undeliverable due to where it is being sent.


  • The recipient no longer works at that company, so their email has been deactivated
  • The recipient's email has not been active in a long time, so their ISP has deactivated the account
  • The email address contains a spelling error

How to Handle

Hard bounces can be very detrimental to your overall sender reputation if not dealt with accordingly. Act-On automatically suppresses (stops sending to) any contacts that have hard bounced. We recommend following our Data Quality Best Practices to clear contacts from your lists after they have been unengaged for some time.

For explanations of bounce reason codes in Act-On, see this page.

Soft Bounce

A soft bounce means that the message was not delivered, but the basic setup of the email was valid.


  • The recipient's email server is rejecting the mail because the sender is not on their safe sender list.
  • The recipient's email provider is rejecting mail due to sender reputation or an increased amount of unsolicited mail.
  • The recipient's email provider saw unusual activity from your sending domain (such as a large number of emails sent from a brand-new domain).
  • The recipient's email server is having a temporary outage.
  • The recipient's inbox is full.

There are a wide variety of other factors that can cause a soft bounce.

How to Handle

Many times soft bounces are temporary, meaning you should try to send them again at a later date. However, a history of repeated soft bounces can bring down your sending reputation. Soft bounces are not suppressed by default in Act-On, so we recommend adjusting your settings to suppress contacts who are chronically soft bouncing without delivery.

For explanations of bounce reason codes in Act-On, see this page.


Emails get added to suppressed lists in Act-On after Hard Bounces, Opt-Outs, Spam Complaints, etc. You can access these lists under Contacts > Other Lists > Bounces and Opt-Outs. You are not able to send messages to these contacts.

Domains Suppressed by Default

Some domains are suppressed by default by Act-On

  • Common Typo Domains: these are domains that are common spelling mistakes from domains that are very well known. These domains are commonly used as spam traps and could have other reputational threats.
  • Role-based email addresses such as info@company.com or sales@company.com, are notorious for generating spam complaints and affecting deliverability. They are frequently one of the biggest sources of spam traps that can land you on the biggest email block lists, such as Spamhaus.


Opted-out contacts have unsubscribed from your emails and therefore can no longer receive your marketing messages. Opt-outs are a natural part of digital marketing, and they do not hurt your reputation. It is important to include clearly visible opt-out links in your emails. Failing to respect opt-outs can result in spam complaints, which do impact your sending reputation.

Returned Messages

For both soft and hard bounces, Act-On records these events automatically and no messages will be returned to you. However, in other cases, your 'send from' email address may receive replies for emails being returned to the sender. Out-of-office messages typically work this way as well.

These indicate that the recipient's email server accepted the message before determining that it could not be delivered. Because Act-On only tracks the initial acceptance, it does not record this as a bounce in our system.

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