When your phone only rings once then cuts out, this fault is known as "ring trip". It can be caused by a number of things either inside or outside your property, and will require a process of elimination to track down the cause of the fault.
2. Enter the destination you wish to transfer the call to, then press [SEND] softkey. 3. Once the receiving party answers, announce the call. 4. To complete the transfer, press again. If you hang up before the call rings, the transfer will fail and the call will be disconnected. Direct to Voicemail: Transfer a call directly to voicemail 1. Press . 2. If a phone rings once and then goes to voicemail or rings only briefly, it You can't definitively know the cause of a phone barely ringing and going to voicemail because neither a phone company nor the phone's operating system provider will tell you if your phone number is blocked.

Unfortunately, there’s no built-in button in your iPhone’s phone app for recording calls. Instead, you’ll have to use a third-party app or service or use a clever workaround.
Setting Up Voice Mail iPhone 7 Tutorial iPhone 7 to Set Up Voice Mail on iPhone 7 is some an easy guide. The first time you tap Voicemail, you're prompted to create a voicemail password and record your voicemail greeting. Listen to a voicemail message on iPhone 7 Tap Voicemail, then tap a message. To listen again, select the message and tap