if mysql donw or/and relaydelay process down ?

hello,
in first sorry for the fist post i had needed just to put this into my sendmail.mc
define(`confMILTER_MACROS_ENVRCPT', confMILTER_MACROS_ENVRCPT``, {i}, {auth_type}, {auth_authen}, {auth_ssf}, {auth_author}, {mail_mailer},{mail_host}, {mail_addr}, {if_addr},  {_}'')dnl

After , i have just a question because i want that my server works if my mysql server is down or if process relaydelay is down or if the both are down.
For mysql down i have use  $pass_mail_when_db_unavail = 1;  but doesn't work i don't know why

thanks for your answer.