The Japanese version of Acrobat pro has "承認用に電子メールで送信" function in "Send For Comments".

In that function, email is sent by each steps of approvement.
but at the final approvement, the following two mails are sent.
1. The xxxx.pdf is completed to approve and sent to @.cp.jp
2. The xxxx.pdf is finally approved.

I think the 1st email is not neccesary on the final approvement.

So please change not to send the confirmation email on final approvement.