Welcome to Over50sForum! The site for people over 50 to chat, make friends, discuss, share, and generally be part of something that's fun and friendly :)
is it a digital landline phone? I don't know the answer to your question but you could try asking a data recovery shop. Maybe there's a flash drive in there or something. In the mean time you would want to switch the answer phone off in case it gets over written with new messages.