On hold messages can be recorded for many purposes, such as promoting your business, answering FAQs or announcing important customer service information. It's important to be clear in the message you are trying to get across. Confusion leads to disengagement and reflects badly on the brand. Determining your callers' wait times is necessary to determine the required length of the on-hold message. Making the recording too short can lead to the message being played too many times. This can be repetitive and lose the caller's attention while they hold.
by Shauna Geraghty · “Thank you for calling X, where customer service is our priority.” · “We are currently unavailable to take your call. Please leave a message or …

There’s a reason this is standard. It starts the conversation off well and pleasantly, and it conveys to the customer that you appreciate them taking the effort to reach out to them. Even though it’s standard courtesy, it still leaves a better impression than a greeting that starts with “You’ve reached our phone line.”
The most professional voicemail message should include a formal tone and specific instructions. For example, you may say “Hello, you’ve reached [your name], [job title] at [business name]. I’m sorry to have missed your call. Please leave your name, contact information, and reason for calling so I can get back to you promptly.”