Of the many things your phone can do, automatically recording a phone call is not one of them. Perhaps not including that feature is a security precaution for phone makers; it could be a potential liability issue. Regardless, from time to time, documenting a call is a useful thing to do, whether you’re conducting a phone interview or cataloging a customer service call.
Voicemail password and greeting. If you haven’t yet set up the Voicemail on your iPhone, the process is easy and onscreen prompts walk you through it. Open the Phone app and select Voicemail > Set Up Now. Create a password and a greeting. If you would like to change your Voicemail password or greeting down the road, these are both simple to

Visual Voicemail works by periodically checking out your voicemail and fetching voice messages along with caller information. It then populates a list which contains the name and the number of the caller, along with the length and priority level of the voicemail.
When recording, choose a quiet area, speak clearly, and use your full name (first and last).