Every voicemail greeting should possess these basic elements in order to provide a clear and concise greeting. Additionally, you will not waste your caller's time by listening to your long-winded greeting.
A short "Hello" or "Welcome to the XYZ Company".
State your full name clearily and pronounce every syllable. If you have a long name, slow down so your caller can hear it.
Your Company Name and/or Department Name
This is especially important for external voicemail greetings. It may be skipped for internal calls.
Statement that you cannot take their call right now
A short statement that you are unable to take the call.
Invitation to leave a message
Invite the caller to leave you a detailed message.
When a return call can be expected
If your policy is to return calls by the end of the day, tell your caller that. If you are away from the office for a week, let them know that too.
Leave a contact for immediate assistance
Nobody like being trapped in "voicemail jail." If there is somebody they can call for immediate assistance, give directions on how to contact that person.
No longer than 20 - 25 seconds
Keep it short. People are busy and don't like wasting time.
Avoid giving out too much information
Provide your callers with only the information they need to leave you a message or get in contact with you.