The reason for the chain delay is to allow people to dial the 1,2 etc after hearing the whole greeting. You can of course dial 1,2 at anytime if you know the option.
Setting the delay to 0 will get the mailbox to chain or move onto the next mailbox as soon as the greeting has finished.
If you put 999 in the chain done then it will go to the hangup mailbox and hangup on the caller.
Glad you are getting the hang of it now.
