You could use Hotmail or gmx.co.uk addresses or Yahoo etc etc. Just go to their homepage(s) and create the email address accounts. You don't need to collect them on your pc's if you don't want to, just have them as Webmail. If you decide to collect on your pc's then you just create a new pop account in Thunderbird and enter the server details so TBird knows where to go to collect them (the pop server settings will be on the homepage(s) site where you create the email address account)
What is ransomware and how do I protect my PC from WannaCry?