diff --git a/rainloop/v/0.0.0/app/libraries/MailSo/Base/HtmlUtils.php b/rainloop/v/0.0.0/app/libraries/MailSo/Base/HtmlUtils.php
index 9fbd1dcc3..2263568a9 100644
--- a/rainloop/v/0.0.0/app/libraries/MailSo/Base/HtmlUtils.php
+++ b/rainloop/v/0.0.0/app/libraries/MailSo/Base/HtmlUtils.php
@@ -484,7 +484,7 @@ class HtmlUtils
 				{
 					$oElement->setAttribute('src', 'javascript:false');
 				}
-
+				
 				if (\in_array($sTagNameLower, array('a', 'form', 'area')))
 				{
 					$oElement->setAttribute('target', '_blank');
@@ -507,6 +507,16 @@ class HtmlUtils
 				@$oElement->removeAttribute('data-bind');
 				@$oElement->removeAttribute('xmlns');
 
+				if ($oElement->hasAttribute('href'))
+				{
+					$sHref = \trim($oElement->getAttribute('href'));
+					if (!\preg_match('/^(http[s]?|ftp|skype|mailto):/i', $sHref))
+					{
+						$oElement->setAttribute('data-x-broken-href', $sHref);
+						$oElement->setAttribute('href', 'javascript:false');
+					}
+				}
+
 				if ($oElement->hasAttribute('src'))
 				{
 					$sSrc = \trim($oElement->getAttribute('src'));