diff --git a/Classes/Service/MailTemplateService.php b/Classes/Service/MailTemplateService.php
index 217a10776f12f88bd0b0ec23a3db0661f3cdcce9..722d26f5512e7feb82af05a058b35e83e40d6365 100644
--- a/Classes/Service/MailTemplateService.php
+++ b/Classes/Service/MailTemplateService.php
@@ -166,13 +166,20 @@ class MailTemplateService {
 		$this->persistenceManager = $this->objectManager->get(PersistenceManager::class);
 
 		// use defaultMailFromAddress if it is provided in LocalConfiguration.php; use the sg_mail TS setting as fallback
-		if ($GLOBALS['TYPO3_CONF_VARS']['MAIL']['defaultMailFromAddress']) {
+		if (!filter_var($GLOBALS['TYPO3_CONF_VARS']['MAIL']['defaultMailFromAddress'], FILTER_VALIDATE_EMAIL)) {
 			$this->fromAddress = $GLOBALS['TYPO3_CONF_VARS']['MAIL']['defaultMailFromAddress'];
 		} else {
 			$this->fromAddress = $this->tsSettings['mail']['default']['from'];
+
+			if (!filter_var($this->tsSettings['mail']['default']['from'], FILTER_VALIDATE_EMAIL)) {
+				$this->fromAddress = 'noreply@example.org';
+			} else {
+				$this->fromAddress = $this->tsSettings['mail']['default']['from'];
+			}
 		}
 
 		$this->mailMessage->setFrom($this->fromAddress);
+
 		$this->bccAddresses = GeneralUtility::trimExplode(',', $this->tsSettings['mail']['default']['bcc']);
 		$this->ccAddresses = GeneralUtility::trimExplode(',', $this->tsSettings['mail']['default']['cc']);
 
@@ -438,8 +445,10 @@ class MailTemplateService {
 		$mail->setExtensionKey($extensionKey);
 		$mail->setTemplateName($templateName);
 		$mail->setLanguage($language);
+
 		$mail->setFromAddress($this->fromAddress);
 		$mail->setFromName($this->fromName);
+
 		$mail->setToAddress($this->toAddresses);
 		$mail->setMailSubject($subject);
 		$mail->setMailBody($emailBody);
@@ -645,11 +654,25 @@ class MailTemplateService {
 	 * @param Template $template
 	 */
 	private function loadTemplateValues($template) {
-		$this->setFromAddress($template->getFromMail(), $template->getFromName());
+		$fromName = $template->getFromName();
+		if ($fromName === '' && $GLOBALS['TYPO3_CONF_VARS']['MAIL']['defaultMailFromName']) {
+			$fromName = $GLOBALS['TYPO3_CONF_VARS']['MAIL']['defaultMailFromName'];
+		}
+
+		$fromMail = $template->getFromMail();
+		if (!filter_var($fromMail, FILTER_VALIDATE_EMAIL)) {
+			$fromMail = $GLOBALS['TYPO3_CONF_VARS']['MAIL']['defaultMailFromAddress'];
+			if (!filter_var($GLOBALS['TYPO3_CONF_VARS']['MAIL']['defaultMailFromAddress'], FILTER_VALIDATE_EMAIL)) {
+				$fromMail = 'noreply@example.com';
+			}
+		}
+
+		$this->setFromAddress($fromMail, $fromName);
 		$this->setCcAddresses($template->getCc());
 		$this->setBccAddresses($template->getBcc());
 		$this->setReplyToAddress($template->getReplyTo());
-		$this->setFromName($template->getFromName());
+		$this->setFromName($fromName);
+
 		$this->setReplyToAddress($template->getReplyTo());
 	}