diff --git a/src/Umbraco.Web.UI.Client/src/common/services/tinymce.service.js b/src/Umbraco.Web.UI.Client/src/common/services/tinymce.service.js
index 493d6faa17..d62f67a5fb 100644
--- a/src/Umbraco.Web.UI.Client/src/common/services/tinymce.service.js
+++ b/src/Umbraco.Web.UI.Client/src/common/services/tinymce.service.js
@@ -850,9 +850,10 @@ function tinyMceService($log, imageHelper, $http, $timeout, macroResource, macro
 				return;
 			}
 
-			// Is email and not //user@domain.com
-			if (href.indexOf('@') > 0 && href.indexOf('//') === -1 && href.indexOf('mailto:') === -1) {
-				href = 'mailto:' + href;
+		    // Is email and not //user@domain.com and protocol (e.g. mailto:, sip:) is not specified
+		    if (href.indexOf('@') > 0 && href.indexOf('//') === -1 && href.indexOf(':') === -1) {
+		        // assume it's a mailto link
+		        href = 'mailto:' + href;
 				insertLink();
 				return;
 			}