I wonder if anyone can help. My landline has changed from analog to digital. The master phone from the old system has a number of messages I’d like to transfer to a computer (ideally) and then delete the messages and recycle the 4 phone system. I have a Lenovo X1 with a microphone but is seems to be intended mainly for voice recognition. There is a headphone socket but no microphone socket. There are USBs of course. The phone has a docking station with a mains connection but no other output. The internet tells me about transferring data from mobile phones but no joy on landlines.
If you can listen to your messages remotely - often possible by phoning yourself then entering a passcode when the machine picks up - you could call from your mobile while recording that call… probably better than microphone at the earpiece. If the landline is disconnected, maybe you’d have to take it somewhere else to give that technique a try though.
I recorded some voicemail messages about 12 years ago by just pressing play with speaker activated, and using the voice recorder on my iPhone. The quality was fine.
Be sure to save a few versions on different emails, devices etc.