Of course you can.

To stop newsletters, notifications, and texts from MadBid follow these simple steps:

Go to My MadBid >> My Information >> Edit Settings and deselect the relevant boxes.

For India: https://in.madbid.com/my/edit_user/
For other countries: https://ud.madbid.com/my/edit_user/

If you change your mind in the future, this is where you can change it back