Each voice mailbox offers 50 minutes of message storage. When 50 minutes are consumed, callers cannot leave messages. Cox Business suggests that you delete older messages, especially large messages, to preserve available storage space. You will receive a warning once the mailbox capacity reaches 70%. The platform will delete any messages after 31 days. What is an extension mailbox, how do I set it up, and how many mailboxes can be attached?
Website: https://support.microsoft.com/en-us/office/make-and-receive-calls-using-skype-for-business-228e03aa-7361-4997-8dfa-1dd9bdc717f6

The unavailable message is the standard greeting callers hear when they reach your voicemail box. It is the greeting that you can use consistently throughout the work year.
And you’re done! Your CenturyLink voicemail is now set up. Whenever you have an unheard message, you'll hear a stuttered dial tone when you pick up your home phone. Take a few minutes to gather your thoughts, even jot down a few notes, and practice before you record. Before you start recording, turn off anything in the background that might cause noise. This will ensure your voice is clear and easy to understand. While clever greetings can be fun, it's worth taking a moment to think about the range of potential callers who may be leaving you voicemail. Consider the tone and image you want to project. Don't worry! If you don't like your recording, you can erase it and re-record as many times as you'd like.