Hi OP,
Hope you're doing okay.
I also receive those spam emails. They're definitely nothing - they're not real sites. You can check if your husband's email was basically sold/stolen for this stuff by searching "pwned" and you can check. Basically my email, my DPs etc has been hacked from very legit websites (such as a teachers website!)
In regards to porn pop ups, I also get those. Do my head in. But only on websites such as to watch American TV and stream - they're frequent. I don't on normal websites such as shopping etc. But that is how targeted ads work.
In regards to porn, I think there's the very obvious thing. You are telling him not to watch porn, but he obviously doesn't think it is a big deal and like a child is saving your feelings to continue to enjoy it, and why shouldn't he? Most people do!
If you're not okay with something, a man will lie. That's what it is. So, unless you absolutely cannot work on this (I genuinely think you'll struggle to find a decent guy who doesn't watch porn to be honest... the stat is that 98% of men ADMITTED to it)
I would say you obviously need help. But you have a loving, caring, and gentle man who has respected you in every other way. His lies are completely understandable - it's easier to lie!
My advice would be not to lose him if you love him.
I would say how about being transparent with porn use - tell me when you use it / don't ever delete history.