postfixadmin/psalm.xml

<?xml version="1.0"?>
<psalm
    phpVersion="7.4"
    errorLevel="4"
    resolveFromConfigFile="true"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="https://getpsalm.org/schema/config"
    xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
>
    <projectFiles>
        <directory name="." />
        <ignoreFiles>
            <directory name="vendor" />
            <directory name="tests" />
            <directory name="templates_c" />
            <directory name="ADDITIONS/" />
        </ignoreFiles>
    </projectFiles>

    <issueHandlers>

        <PossiblyUndefinedGlobalVariable>
            <errorLevel type="suppress">
                <file name="config.inc.php" />
                <file name="config.local.php" />
            </errorLevel>
        </PossiblyUndefinedGlobalVariable>

        <InvalidGlobal>
            <errorLevel type="suppress">
                <file name="config.inc.php" />
                <file name="common.php" />
            </errorLevel>
        </InvalidGlobal>
        <LessSpecificReturnType errorLevel="info"/>

    </issueHandlers>

</psalm>