diff --git a/pandora_server/lib/PandoraFMS/Core.pm b/pandora_server/lib/PandoraFMS/Core.pm
index ecac3c50b2..47b8e324ac 100644
--- a/pandora_server/lib/PandoraFMS/Core.pm
+++ b/pandora_server/lib/PandoraFMS/Core.pm
@@ -1073,7 +1073,7 @@ sub pandora_execute_action ($$$$$$$$$;$) {
 		# non-ascii chars should be encoded in UTF-8.
 		if ($field3 =~ /[^[:ascii:]]/o) {
 			$field3 = encode("UTF-8", $field3);
-			$content_type = 'text/html; charset="UTF-8"';
+			$content_type = 'text/plain; charset="UTF-8"';
 		}
 		
 		# Build the mail with attached content