No doubt, you are a good CM, I've worked with you, but telling a new member to directly contact you when he knows nothing about you could be a bit odd/off. Don't you think you should let him know what you do on the forum as CM, with a redirecting link to your marketing page to avoid suspicion since he doesn't know who is who yet?
As a company, if they want to run marketing program and want to hire a campaign manager do to it for them, after receiving this offer, they will see no issue to ask for more information.
A campaign manager can not send PM first because forum rule does not allow it. So if the company are interested in the offer, it's easy to write a short reply, and ask for more details, then discussion can be changed to PMs.
I don't see big issue with this offer from yahoo, and the impression with high green trust is more than any introduction. I see you have good intention to help, but I only disagree with it, and have no intention to offend you.