4.) Bienvenido/a al despacho del señor John Doe. En estos momentos no se encuentra en su oficina. Por favor, deje un mensaje para que el señor Doe pueda llamarle lo antes posible. Muchísimas gracias por su llamada.
iPhone recorder apps only work because they utilize 3-way conference calls, either incoming or outgoing. The third "caller" is a recording line, provided by a service from the app's developer. Obviously, 3-way calling is a must-have feature of your iPhone for this to work, so be sure your carrier supports it. In the US, the big three all do, but some smaller carriers do not—at least not in a way these apps support.

Need to change your voicemail greeting on the iPhone? If you never recorded one and want to record or change a voicemail greeting, you've come to the right place.
With this method, you don’t need a third-party app. Call the person you want to chat with, then tap the “Add Call” button on your phone’s screen. Dial your own phone number—the one you’re calling from. This will take you to your voicemail. Once your voicemail has started recording, tap the “Merge Calls” button on your screen. Now, you’ll record your phone conversation onto a voicemail message. When you’re done with the call, you can tap the share button to export it to your Mac via Airdrop, to the Voice Memos app, or transfer it via email or text message. The file is recorded as an M4A, so depending on what you want to do with it, you may need to convert it to MP3 before uploading it to other apps.