diff --git a/mail/js/app.js b/mail/js/app.js
index d3fc40f9e7..68847d67b1 100644
--- a/mail/js/app.js
+++ b/mail/js/app.js
@@ -3036,12 +3036,12 @@ app.classes.mail = AppJS.extend(
 			var _id = _elems[i].id;
 			var dataElem = egw.dataGetUIDdata(_id);
 			var subject = dataElem? dataElem.data.subject: _elems[i].subject;
-			if (this.egw.is_popup())
+			if (this.egw.is_popup() && this.et2._inst.name == 'mail.display')
 			{
 				subject = this.et2.getArrayMgr('content').getEntry('mail_displaysubject');
 			}
 			// Replace these now, they really cause problems later
-			var filename = subject.replace(/[\f\n\t\v\/\\\?]/g,"_")|| 'unknown';
+			var filename = subject ? subject.replace(/[\f\n\t\v\/\\\?]/g,"_") : 'unknown';
 			ids.push(_id);
 			names.push(filename+'.eml');
 		}