These are 100% not offers that should be accepted. None of these casinos are licensed in the UK - one is a bitcoin casino (and not even one of the well known ones), one is forbidden when I visit from the UK, and the third offers a 400% welcome bonus in pounds for UK players despite not being licensed in the UK.
In my experience, any casino that you haven't signed up to that sends you an email unprompted probably isn't going to be reputable. UKGC licensed casinos wouldn't send correspondence to a random email address asking them to sign up. Please don't take any of these offers, but I will be hiding the images from your post, just because I wouldn't want someone else to see and be tempted 🙂