Like all immoral things, it's only bad if you get caught. :( Most perpetrators will nog blog their shenanigans.
I wouldn't have figured out this was Ai, and might have engaged had if the topic was relevant to me. I would not have engaged with a traditional spam email even if it had been relevant to me, so there's a real incentive to do stuff like this.
I highly doubt that people employing this scheme are thinking it through though. Lets say you indeed engage with this email, not knowing its AI. Then when things are getting serious a human approaches you after all and you find out you were talking to AI all the time. Would you not be completely outraged by being fooled like this?
I think marketers underestimate that they may turn people off their brand in the long run by these tactics, because people do not like being fooled. And the more sophisticated the scheme the more outraged people are when they find out.
I would be outraged IF I found out. If the AI-to-human hand-off is smooth enough, there is no way to figure this out. In your scenario, if the AI's only task is to send gazillions of emails to generate leads, and then the human takes over when the leads come in, the respondents have no way to figure out that the initial email was an AI.
Of course, the answer is to have AI send a response with a CAPTCHA (assuming those still work), before showing the initial email to the recipient.
I wouldn't have figured out this was Ai, and might have engaged had if the topic was relevant to me. I would not have engaged with a traditional spam email even if it had been relevant to me, so there's a real incentive to do stuff like this.