The DropList, also known as the mail blacklist, is a collection of
domains and email addresses that are denied from sending emails within the system.
It is disabled by default.
To enable it, modify the `droplists.properties` file and include the `IsInDropList` matcher in the `mailetcontainer.xml`.
To disable it, adjust the `droplists.properties` file and remove the `IsInDropList` matcher from the `mailetcontainer.xml`.

.droplists.properties content
|===
| Property name | explanation

| enabled
| Boolean. Governs whether DropLists should be enabled. Defaults to `false`.
|===

== Enabling Matcher

Plug the `IsInDropList` matcher within `mailetcontainer.xml` :

[source,xml]
....
<mailet match="org.apache.james.transport.matchers.IsInDropList" class="ToProcessor">
    <processor>transport</processor>
</mailet>
....

== DropList management

DropList management, including adding and deleting entries, is performed through the WebAdmin REST API or CLI.

See xref:{pages-path}/operate/webadmin.adoc#_administrating_droplists[WebAdmin DropLists].
See xref:distributed/operate/cli.adoc#_manage_droplist[CLI DropLists].