diff --git a/apps/files_sharing/lib/Controller/ShareAPIController.php b/apps/files_sharing/lib/Controller/ShareAPIController.php
index cf83587467724..5050d7bb63642 100644
--- a/apps/files_sharing/lib/Controller/ShareAPIController.php
+++ b/apps/files_sharing/lib/Controller/ShareAPIController.php
@@ -658,8 +658,24 @@ public function createShare(
 		$this->checkInheritedAttributes($share);
 
 		// Handle mail send
-		if ($sendMail === 'true' || $sendMail === 'false') {
-			$share->setMailSend($sendMail === 'true');
+		if (is_null($sendMail)) {
+			// Define a default behavior when sendMail is not provided
+			if($shareType === IShare::TYPE_EMAIL) {
+				// For email shares, the default is to send the mail
+				$share->setMailSend(true);
+			} else {
+				// For all other share types, the default is to not send the mail
+				$share->setMailSend(false);
+			}
+		} else {
+			// Convert common "truthy" and "falsy" values to proper booleans
+			$sendMailBool = filter_var($sendMail, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);
+
+			if ($sendMailBool !== null) {
+				$share->setMailSend($sendMailBool);
+			} else {
+				throw new OCSNotFoundException($this->l->t('Invalid value for sendMail'));
+			}
 		}
 
 		if ($shareType === IShare::TYPE_USER) {