Your inbox is full. Or at least, that's what Gmail says whenever I try to send you an email.
woah i didn't know that could even happen...? i tried sending myself an email from another account and it worked just fine... i'll try deleting stuff anyway. all i can think of is try doublechecking that the address was right haha. or if you're attaching something to the email try hosting it on google drive instead and sending a link? (i don't know if that's what you were trying to do, if not i'm confused as you are lol)