Sure. Basically please follow the instructions here: in manual “Using edgeryders.eu e-mail addresses”, section “3. How to receive and send edgeryders.eu e-mails with Thunderbird”.
That will give you access to your e-mails directly, without you going to your Gmail account to see them. Once you have that access, tell me here and I’ll switch off the forwarding of marina@edgeryders.eu e-mails to your Gmail address. For good measure, I’ll also tell you your e-mail password again over Matrix chat now.
@alberto, you can go through the same process already if you currently receive your alberto@edgeryders.eu e-mails through your Gmail account. I will check and see who exactly is affected, that is, for whom a forwarder to a Gmail address is set up currently.