How come my full name shows up when i send someone an email instead of just email address?

Something has to show up in that space (according to Yahoo)----BUT it doesn't have to be your name. It can be a nickname---or your initial (J)---or even the email address itself. You just need to change the "from line" setting. This works for either version (Classic or New Mail). Mail page>>options>>mail options (or "more options" on the New Mail)>>Accounts (from the list on the left)>>then click on "Yahoo Mail"---(middle of page, under "Accounts"). Now you can erase whatever is showing, on the "From line" and type in something else---a nickname----OR your own name ---or whatever---THEN click "save" changes at the top of that page. You CAN NOT leave that line blank, otherwise Yahoo enters what was previously there or even sometimes puts "False" in place of a name. Some people say you have to log out and then back in, for the changes to be effective----but some find it's "not necessary"-----maybe it depends on your computer ??