Gmail has this convenient way to 'send email as' another account, to make it appear like the email came from that account rather than the Gmail mailbox. A great way to hook up your domain to your Gmail but still rely on Gmail's great SMTP servers. To get this started, you have to send a verification/permission request email to the concerned email address. Nice and safe.
However, I have a question with regard to revoking this verification afterwards.
Say I no longer have access to the Gmail account that can send on behalf of my @mydomain email account (as I've previously verified that it could do this). Is there a way to revoke this permission? I realise I can delete the alias from the Gmail account, but what if I do not have access to the account, and can only access the @mydomain email address? Can I force Gmail to re-verify?