Companies sharing your email address

[Fly]

I signed up for a Tesco credit card. The small print said we may share your email with other like or trusted companies.
Fair enough I thought, so I used a personal email address, tesco @ ***********.**
A few weeks later, I started to receive loads of spam offers, deals, etc from various companies at that email address 
I managed to unsubscribe from most of the mailing lists, so all was fine.
I also logged into my card account and changed my email to tesco2 @ ***********.**

Yesterday I received yet another spam email sent to tesco @ *********.**

How are you ? How are you currently doing? I love your profile.

Want to view my personal photographs?

Message me at daniceyjf181 @ hotmail.com and i will reply back with my private pictures.

Checking the email properties I find it was sent from ztuqixul @ grewalsingh.com
A quick google of grewalsingh.com comes up with this, www .cagrewalsingh. com

A New Delhi chartered accountant 
Tesco's, Every little helps