reworked online_detect to the simpler online_query Only pipe is supported now. Use online_query="/bin/cat /path/to/file" instead of online_detect=file online_file=/path/to/file and online_query="/path/to/some/script foo" instead of online_detect=pipe online_pipe="/path/to/some/script foo" See man page masqmail.conf(5) and admin/config-transition.