Getting an email via InMotion for non-existing email account that is hosted on Hostinger

Hello,

I received an email like this: https://shrtm.nu/e25

And when I look into the header, it is coming from InMotion. 

I reach out to my host Hostinger, and they tell me to contact InMotion even though I've never hosted with InMotion before. They said it might be possible previous owner had hosted with InMotion... even though I own this domain for over 5 years.

Can anyone tell me what may be going on here? Or how do I reach out to InMotion support about this?

Here is the email header information: https://shrtm.nu/e26