First, the withdrawal mail must be sent from the trademark or patent registration mailbox of the obligee to take effect.
For example, when I registered my trademark in the Trademark Office, I used email A, so the withdrawal email I sent to Amazon must also be sent from this email to be considered valid. It is invalid to send it through the B mailbox of the obligee.
Second, you can ask the obligee to send you a copy when sending the withdrawal letter, so that you can confirm whether it is really sent. Second, you can check whether the withdrawal method is correct.