You can manage greetings for Call Groups, Call Queues, Extensions, and Virtual Receptionists in your Online Account. This includes the Voicemail greetings for these features.
While access to greeting options can vary by feature, the controls to play, record, upload (import), and download are the same across all.
NOTE: If the voicemail box is full (5000 Messages), a greeting that states "I'm sorry. This mailbox is full." will play until some messages are deleted.