Voicemail recordings are controlled by the Mitel PABX itself. Amethyst does not record or maintain this function.
To get a perspective, when a call goes to voicemail the PABX records the call left as a voicemail.
This will happen regardless of if the company has a recording solution or not.
The might not be a default setting on Mitel but it can be configured by the PABX vendor.
The voicemail function can then be automatically emailed to the addresses link to this function.
For this function, consult the PABX Vendor.