Business professionals are also encouraged to keep their voicemail organized. Delete any messages from the office phone that are no longer necessary after calls are returned, and write down any phone numbers that are needed at the time the message is listened to. If modern voicemail service is utilized, such as that supplied by Voicemail Office, in which voicemail and fax messages are received in a staff member’s email inbox, the individual should write a short explanation in the body of the email if forwarding any voicemail messages to other staff members.
Your voicemail greeting is the message your callers hear when they reach your voicemail. There are two types of voicemail greetings - Busy and No Answer. The Busy greeting is played when you are on another call and do not have call waiting, and the No Answer greeting is played when you do not answer the call.

Record a voicemail that is as unique as your business, and add a human touch when creating the message. Encourage your caller to leave a message describing what their needs are.
Context does matter here. If the caller would reasonably expect you to answer the phone (such as if they were calling a store or other place of business), an apology for not being able to get to the phone makes the most sense.