my mail log say "permision deny" when mail.local try to lock the user mail file :
Dec 8 17:54:59 localhost mail.local: setreuid(0, 501): Operation not permitted (r=501, e=501)
Dec 8 17:54:59 localhost sendmail[2058]: fB8Gswn02057: to=, ctladdr= (501/20), delay=00:00:01,
the...