Vivinavi

I am having trouble dealing with a defamatory spam email from a person named "Hiro-san" （ Please reply to female only ）.

I am a working woman who received your help last year with advice on moving, medical care, etc. I am very grateful for the advice and kind words of encouragement I received from many people through Vivinavi's message boards.
Since I started posting here, I have been receiving emails from a person with the handle "Hiro-san", regardless of the content, and I don't know if it is just for women or if other people have experienced this, but the content of the emails is unrelated to the question and the emails are slanderous and critical. I don't know if other people have experienced this, but I have used the block function, but I am still having trouble because the account has been changed and I am still receiving messages under the same name
I wish I could go through with it, but due to my email application, the messages I receive via Vivinavi are received together, so I am unable to avoid only the messages from "hiro-san".
I am forced to look at the slanderous mails that I receive every time.
If there are any women who have received similar mails and know how to deal with them, I would appreciate it if you could contact me.
（ Please do not send any defamatory or critical emails ）.