But what’s really great about Samsung’s way of dealing with voicemails is the new and improved Visual Voicemail service. This lets you view voice mail messages and listen to them in any order you want. Instead of listening to all of them in order, you can pick the ones you’re interested in. Even more, you can decide to erase or archive them, all from your device screen. Visual Voicemail also includes button shortcuts to call back or text a person that left you a voicemail.
Website: https://www.leawo.org/entips/how-to-record-voicemail-on-iphone-1114.html

If you persistently can’t save your greeting, you may need to reset your phone’s network settings. The iPhone needs to access your network’s data connection to save changes to your voice mail configuration, and if it can’t connect to 3G or 4G, it won’t save the changes.
Voicemail access and the initial password should have been set by your carrier or service provider when your device was first activated. But keep in mind that some carriers don’t use passwords when it comes to voicemail. If you don’t know if this service is enabled or you forgot the password, you should check in with them first. If you see the contact list opening, tap on the phone dialer icon located in the bottom-right corner.Once you’re in keypad dialer, touch and hold on number 1 key. Now one of two things can happen. One, if you the service is enabled your phone will dial the voicemail number and prompt you to insert or create a new password. You might also be asked to record the greeting message at this stage. And two, in case your carrier didn’t configure this service when your device was first activated, you’ll be prompted with a message to insert your voicemail number. If the first scenario is the case, follow the instructions provided by your carrier to finish setting up your voicemail. In the event that you’re prompted to insert your voicemail number, tap on Add Number. If you don’t know your voicemail number, call your carrier and ask for it or search online for something like “voicemail number + *YourCarrierName* + *YourCountry*”. Now follow the instructions provided by your service provider to finish setting up your voicemail. Note: If you bought a used phone or you recently changed the service provider, chances are you have the wrong voicemail number set up. In cases like this, open up the App drawer and tap on Phone. From there, tap on More and select Settings. Once you’re in Settings, scroll all the way down to Voicemail settings and tap on the entry. This will open a pop-up in which you can change the voicemail number.