Using the University email account is mandatory. If you are not planning to use it actively it would be good to forward the emails to another personal account.

To forward the emails to another account you have to log in gmail.tlu.ee and go to „Settings“ → „Forwarding and POP/IMAP“ → „Add a forwarding address“.

After entering your personal email address a confirmation link will be sent there. That link has to be activated for the forwarding to start.