I can’t change my email on Lines. I had the same issue on Elektronauts and after a lot of back and forth the problem was located:
I checked our smtp server and your email was suppressed as it had previously bounced. I removed the suppression so you can try again.
And when I tried again, this time I received the confirmation email and all was well again.
To whom should I contact on Lines in order to un-suppress my new address?