Delivery time/email Ishida JP Post questions?

Hi dear Loli's,

I tried to look this up, but I did not come to a good conclusion.

I bought a dress from a person in Japan. He said the package was shipped the 9th of May, insured. 
I got the tracking number. It looks like this:
JPIxxxxxxxxINSD

Now he said I only can track it by email to this email:
j.p.insurance.europe.ishida@gmail.com

I really want to know first if the email is a real official email address for jp post. Because mostly you just check its status online.
So I find it weird, that you need to email them. I would like to know if this is normal?
Secondly I would like to know what the delivery time is, from Japan to the Netherlands, insured?

Thanks in advance,

Yvette