Nothing in the spam folder or elsewhere.
I think he didn't create the account, having done it from the android app.
But so I have lost all the bookmarks.

@leocg

I did another test, I created a different account from the web page (not from the Opera android) and I sent the recovery email, in this case I received it. Unfortunately with the previous account, the one where I had the bookmarks, I created it from the browser itself (from Opera app, settings - create account). I think it didn't create or synchronize absolutely anything

I had created an account on the Opera browser for Android, to have a backup of all bookmarks. Then I uninstalled the browser and reinstalled it later. Once he tried to log in again he didn't recognize my password, saying it was wrong.
So I tried to reset my password, sending an email to my mailbox, but nothing comes. I have tried a hundred times but to no avail. To give it a try, I created another account, with a different email address, thinking that on the first account I blocked the reception of emails, but not even on the other I receive emails to reset the password. Simply those emails are not sent.
Can you tell me how to reset this password? I have to get my bookmarks back.