diff -Naur claws-mail-3.13.0.orig/src/summaryview.c claws-mail-3.13.0/src/summaryview.c
--- claws-mail-3.13.0.orig/src/summaryview.c	2015-10-14 23:55:44.671597103 +0300
+++ claws-mail-3.13.0/src/summaryview.c	2015-10-14 23:55:44.741597119 +0300
@@ -4651,6 +4651,10 @@
 		summary_msginfo_unset_flags(msginfo, MSG_DELETED, MSG_MOVE);
 	}
 	if (!prefs_common.immediate_exec) {
+		if (to_folder->stype == F_TRASH 
+			&& MSG_IS_UNREAD(msginfo->flags)) {
+			summary_mark_row_as_read(summaryview, row);
+		}
 		summary_set_row_marks(summaryview, row);
 	}