Scam
this isn’t a scam
it’s our official Affiliate Invitation Program, and you’re welcome to join!
I cannot say 1 way or the other if this is a scam, but the way you are not posting any information about the site or what you are asking people to join comes off as a big red flag. I wouldn't recommend anyone contact you as that's also a scam tactic.
If you're legit, post some links and or images of whatever you are trying to promote. Let people see and decide whether to trust you.
Images actually won't do, if truly he is not here to scam, and that this so called affiliate program isn't a scam, then I am expecting him to explain in full details what the program is all about, provide link to the site and explain in details how any body interested in the joining the affiliate program can sign up successfully without having to contact him (the op) first..
Then, he should proceed to explain in details what is expected of the affiliate member, goals that are expected of him or her to achieve to guarantee earnings.
He should state everything clear and understandable well enough that no one will have any need of contacting him privately for any further information, this will tell us all if this is something worth giving a try or not without reaching out to the op himself.