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.
i love that device – i build one as you described above and at the end i used a professional voicemail greeting from https://voxendo.com/en/voice-prompts-and-telephone-messages/ It looks like Twillio charges by the minute even though it appears that the voice file gets saved on the Pi. I’d like to use this to record phone calls by patching it in like adding a third party using the three-way function on my cell phone.

Don’t include the date unless it’s completely necessary. 16 of the messages I heard last month had the wrong date—one of the messages had a date over 2 months old!
You can fine-tune this similarly to how companies A/B test their websites, ads, call scripts, and anything else that requires a change. The more elements of a call you look at, the more likely you’ll be able to optimize your voicemail greetings. If you jump right into the greeting without saying “Hello,” go back and make your greeting more personal on the second attempt.