# Free email output can be used as a parameter for custom rules

_November 16, 2023_

> **⚠️ Warning**
>
> This release note is more than two years old and may no longer reflect
> current behavior. View the
> [latest release notes](/minfraud/release-notes/).

You can now use the `/email/is_free` output in minFraud custom rules. This
output is available for transactions submitted through minFraud Insights and
minFraud Factors when you pass the `/email/address` input as plaintext, or when
you pass an MD5 hash of the `/email/address` and the plaintext `/email/domain`
input.

Use of free email providers (e.g. Gmail, Yahoo, Outlook, etc.) by consumers is
the norm, so filtering transactions on this data point is often useful only in
business-to-business contexts where you expect transactions to be conducted
using a business email domain.

You can select the free email output as a parameter in custom rules by selecting
minFraud outputs > Is free email when defining a new condition for a custom
rule.

- [Learn more about setting custom rule conditions on our Knowledge Base.](https://support.maxmind.com/knowledge-base/articles/create-a-custom-rule-minfraud-maxmind#create-custom-rule)
- [Learn more about free email detection on our Knowledge Base.](https://support.maxmind.com/knowledge-base/articles/minfraud-email-risk-data#email-reputation-flagging)
- [Learn more about passing email inputs on our Knowledge Base.](https://support.maxmind.com/knowledge-base/articles/passing-email-inputs-minfraud)