they sent me a cashier check

Care to tell us a bit more, or do you want to leave us in suspense?
Did they want you to green dot some money to them, before receiving the check?
If so, did you send them money?

OR
Did you post that phone number here, so people wanting cashiers checks would call it?

Then what? They did the same to me..

They emailed me wanting to put in Mary Kay order n left this number to contact them

They contacted me regarding wanting to order Mary Kay and said they was going to send me a cashiers check wanted all my personal information including address.. She said she with a modeling agency. This is a fraud don't get caught up will send u cashiers check us have to send part of it back then u end up owing bank when they find out its a scam