Sounds like Delilah could use some socializing and supervision, and your mail carrier could use a new job. She is acting very childish but writing things down for you rather than talking about it like an adult. When Autumn was young I took her out each day to see the mailman so she would get used to him and let him do his job. She only runs up to him when I say its okay, she isn't allowed to run up to anybody without permission.