When you hear the Dial Tone, call into your landline or office voicemail box. The rule of thumb is when you hear the Voicemails Forever dial tone, then follow your phone's instructions to listen to your voicemails remotely. This will vary from carrier to carrier and phone to phone. You may need to call your phone networks customer support for updated instructions.
When recording, choose a quiet area, speak clearly, and use your full name (first and last).

The importance of voicemail in the customer care sector has not diminished despite the arrival of newer web technologies. VoIP applications let the businesses use voicemail service with flexibility, as it is. The users need not rely on extension terminals when they use VoIP services. A strong internet connection is a prerequisite and the pre-configured phones can be used – both for calling /receiving calls and for automated custom greetings. IVR feature redirect callers to the right virtual extension where their needs can be addressed. This can be done anywhere through a web portal access and an internet connection.
Before the digital era, he says more than 80 percent of business lines had voice mail. Now, he estimates only a third of office phones have it.”For customers, even the most professional voicemail greeting is impersonal, and may even harm customer experience (millennials, in particular, avoid using voicemail altogether).