It is possible to modify the email associated with your TPOP account, very simply.
On your TPOP dashboard, click on "Preferences" at the bottom left.
Then, in the "Email" section, simply enter your new email address and voilà.
How can I change my login email? How do I change my login email? How can I change my email address? Wie kann ich meine Anmelde-E-Mail ändern? How do I change my login email?