How are scammers sending scam emails from a real t-mobile email address

I'm new at this and technoligically challenged.  I really don't know how to participate in this community chat.  So I just thought this was a scam, and people should know.  I do not like the criminal scammers invading my space at my expense.  They should be technoligically disabled from their predatory practices.  I'm sure we have technical ways to stop these criminals.  Why are the customers left with the liability!  Not right.