Say that your prospects want to speak to the sales department and so when they realize that they have reached the right department and hear the voicemail messages, they will be compelled to leave their contact details so that the sales team can reach out to them later. They will be relieved.
Expanding on the simple approach above, let the caller know who they've reached. This will not only eliminate people leaving voicemails by mistake, but it will reassure the caller that they have called the number they intended.

Your message is a period of time that they are forced to wait through in order to do what they called to do in the first place — relay information to you.
Creating a professional voicemail greeting isn’t complicated, but you need to keep a few things in mind to ensure success. The following tips will help: Be friendly and welcoming - let your company's personality shine!; Have a clear voice, speak at a slow to moderate pace, minimize background noise; Ensure the greeting is human and approachable; Keep the greeting short and informative; Ensure the greeting doesn’t sound robotic or unnatural; Show your gratitude for the call by saying thank you; Manage expectations by clearly stating when the client can expect a callback.