Forward to specific Voicemail depending on source extension

Hey folks,

here is the scenario i have to set up:

Incoming call to extension 120. Extension 120 is anavailable therefore call is being forwarded to central extension 100. If 100 does not answer voicemail of extension 120 has to answer. If 100 is called directly and not being answered, voicemail of 100 has to answer, the common voicemail for the company.

If a certein person in the company is being called and not answering, the call has to be forwarded to the secretary. If secretary does not answer the call has to go to the specific mailbox of that certain person.

Any ideas ?

Thanks in advance. Best regards

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