Introduction: Recipient Filter

Table of contents:

  1. What is the Recipient Filter?
  2. How do recipients end up on this filter?
  3. Where to find the recipient filter?
  4. Adding, importing, or exporting filtered recipients
  5. Removing filtered recipients

When a message returns with the notification: 'Filtered', it means the message's recipient is on our Recipient Filter.

What is the Recipient Filter?

Flowmailer's Recipient Filter is a list of email addresses to which your account should no longer send emails. In case of a hard bounce, for example, there is no use in trying to send to a broken address over and over. In fact, that may be regarded as spammy behavior.

Whenever a sender attempts to send an email to a recipient on this list, the system will trigger a bounce message saying your message has been filtered. It will also mark the message in Flowmailer with the status Rejected. The recipient filter is account-based, meaning that a filter in one account has no effect on sending in another account. The affected account will email that recipient again after removing the filter.

How do recipients end up on this filter?

Email addresses on the filter list are blocked based on feedback the receiving mail server initially gave about that email address. To end up on the filter, Flowmailer was either not allowed or not able to deliver to that address. Typically, that means a hard bounce, but we also filter recipients that marked your email as spam (complaint). Technically, SMS recipients can also end up on this list, but only after meeting specific requirements or after manual upload.

Soft bounces

Soft bounces are not added to the filter immediately. Still, if we only log (a lot of) soft bounces for an extended period of time, Flowmailer assumes this is a permanent situation, and the address is added to the filter.

The grace period

If a message is added to the recipient filter for the first time, and it is not a complaint, Flowmailer will automatically remove the filter after one week. However, the grace period does not apply if the address is listed again.

Where to find the recipient filter?

You can access and edit the recipient filter if you are either an Admin, Designer, or Servicedesk user. From the Dashboard, navigate to Reports and select 'Recipient Filter'. This provides you with the complete list of filtered email addresses, where you can filter on date or email address. The columns in the overview also provide insight into why these addresses have been blocked. From the recipient filter overview, you can also find the message details that caused the filtering, like below. Click the download icon in the timeline to see the original bounce message.

Timeline for a hardbounce ending up on the recipient filter

Adding, importing, or exporting filtered recipients

In case you need to manually transport your filtered recipient list to prevent being sent emails to or to internally share the data with, e.g., Business Intelligence or Customer Service departments, the recipient filter allows you to add, import, and export the filtered recipients. 

The recipient filter

Add filter (button)

By clicking the 'Create recipient filter' button, you can manually add an email address to the filter list. This allows for a single filter per time:

Manual recipient filtering

You cannot use the recipient filter to preventively block email addresses from being emailed. On the recipient filter, you can only add complete email addresses, no wildcards (e.g., * This can be done, however, by adding a Discard step to your email flows:


Import filters (left icon)

The import icon will prompt a screen with instructions: The import file should be in CSV format. Fields should be separated by commas and enclosed in double quotes. The first row (table header) should contain the following fields: address, type (EMAIL/SMS), date, and reason. If you have one reason for the entire upload or a few values are blank, you can use a default value for the missing values, for example, "spam complaint". 


Exporting filters (right icon)

You automatically download a comma-separated file with the filtered recipients by simply clicking the export icon. Be mindful that this is still considered personal data, as complaints concern real email addresses. These files should not be shared with everyone.

Removing filtered email addresses


While it may very well be that the underlying problem has since been resolved, we don't just randomly put addresses on the filter. Something happened before it was put there. Though you can remove recipients from this filter, we urge you to do so with care. 

Complaints are a special case. Clients do make complaints without realizing what that means. Often, we see customers reach out to a brand, saying they're not getting emails anymore. On other occasions, a complaint on a marketing email could also mean that your invoices are not being delivered anymore. In both examples, there are good points to be made about removing them from the recipient filter. That said, proceed with caution, especially in the case of complaints.

Whitelisting recipients

When you're testing or have a set of trusted domains, you can also manage a set of whitelisted addresses and domains. You will find this list in the navigation under Setup > Settings. In Account Settings, you can add new items in the white field under "Recipient whitelist":