diff --git a/Build/phpstan/phpstan-baseline.neon b/Build/phpstan/phpstan-baseline.neon
index 8167cbc2c1964a79b4fea03c6e07259ca556e93f..dc5974dcf55c3aa772812c3b5663c763e42af473 100644
--- a/Build/phpstan/phpstan-baseline.neon
+++ b/Build/phpstan/phpstan-baseline.neon
@@ -1825,16 +1825,6 @@ parameters:
 			count: 1
 			path: ../../typo3/sysext/core/Classes/Utility/IpAnonymizationUtility.php
 
-		-
-			message: "#^Method TYPO3\\\\CMS\\\\Core\\\\Utility\\\\MailUtility\\:\\:getSystemFrom\\(\\) should return array but returns null\\.$#"
-			count: 1
-			path: ../../typo3/sysext/core/Classes/Utility/MailUtility.php
-
-		-
-			message: "#^Method TYPO3\\\\CMS\\\\Core\\\\Utility\\\\MailUtility\\:\\:getSystemFromName\\(\\) should return string but returns null\\.$#"
-			count: 1
-			path: ../../typo3/sysext/core/Classes/Utility/MailUtility.php
-
 		-
 			message: "#^Method TYPO3\\\\CMS\\\\Core\\\\Utility\\\\MathUtility\\:\\:calculateWithParentheses\\(\\) should return int but returns string\\.$#"
 			count: 2
diff --git a/typo3/sysext/core/Classes/Utility/MailUtility.php b/typo3/sysext/core/Classes/Utility/MailUtility.php
index 4437546a64e8b328f29e6cdf5f7d9c5e74e4190b..57bdf1dadd3fba387f97d107f0dd68dcd3892d86 100644
--- a/typo3/sysext/core/Classes/Utility/MailUtility.php
+++ b/typo3/sysext/core/Classes/Utility/MailUtility.php
@@ -27,7 +27,12 @@ class MailUtility
      *
      * Ready to be passed to $mail->setFrom()
      *
-     * @return array key=Valid email address which can be used as sender, value=Valid name which can be used as a sender. NULL if no address is configured
+     * This method can return three different variants:
+     * 1. An assoc. array: key => Valid email address which can be used as sender; value => Valid name which can be used as a sender
+     * 2. A numeric array with one entry: Valid email address which can be used as sender
+     * 3. Null, if no address is configured
+     *
+     * @return array<string|int, string>|null
      */
     public static function getSystemFrom()
     {
@@ -47,7 +52,7 @@ class MailUtility
      *
      * As configured in Install Tool.
      *
-     * @return string The name (unquoted, unformatted). NULL if none is set
+     * @return string|null The name (unquoted, unformatted). NULL if none is set or an invalid non-string value.
      */
     public static function getSystemFromName()
     {
@@ -90,7 +95,13 @@ class MailUtility
      *
      * Ready to be passed to $mail->setReplyTo()
      *
-     * @return array List of email-addresses. Specifying a realname can be done in the form of "replyToName <replyTo@example.com>".
+     * This method returns a list of email addresses, but depending on the existence of "defaultMailReplyToName"
+     * the array can have a different shape:
+     *
+     * 1. An assoc. array: key => a valid reply-to address which can be used as sender; value => a valid reply-to name which can be used as a sender
+     * 2. A numeric array with one entry: a valid reply-to address which can be used as sender
+     *
+     * @return array<string|int, string>
      */
     public static function getSystemReplyTo(): array
     {