Email address texting him?🤔

Hey ladies I need some advice or clarification.

So this “random” email address has been sending my husband text messages (not emails). In the message it’s always links to a porn websites.

He claims that he doesn’t get on the internet on phone to even have those message be sent to him.

So my question is: are those message just spam like you would get in your email or is it from actually being in those websites?

I have talked to him about it and all he said is “I don’t be doing anything on my phone, I get random message all the time from subway and dominos too” ( he has an account with subway and dominos)

What do y’all think.