I'm installing Zimbra 6.0.5 on SLES 11 64 bit and working sucessfully until now, but I'm curious regarding the above message (as on tittle) on /var/log/zimbra.log.

What is the main problem that produce following message :
OTP unavailable because can't read/write key database /etc/opiekeys: Permission denied
Note : Zimbra has no problem on production both sending and receiving email.