Package managers
Package composer1 uses a default repository2 that includes non-free software (e.g. mageplaza/module-smtp3). If you do not want to purge the package, you could remove the default repository with this patch:
/usr/share/php/Composer/Config.php
@@ -119,7 +119,7 @@
// load defaults
$this->config = static::$defaultConfig;
- $this->repositories = static::$defaultRepositories;
+ $this->repositories = [];
$this->useEnvironment = (bool) $useEnvironment;
$this->baseDir = $baseDir;
The same might happen with other package managers like pyton-pip4, npm5, ruby-rubygems6, carton7, cargo8 or golang-glide9.