My dog is a maniac every single day when the mailman comes. She jumps up on the couch so hard that I'm surprised the back of it hasn't slammed through the Livingroom window yet. She gets so loud and throws a FIT if she doesn't get outside fast enough to bark her face off. Yelling at her for it never works. She goes straight psycho with 100% of her attention focused on the Mail. She isn't aggressive toward me or would bite the guy or anything, she's just a ball of energy. 

I'm not looking forward to this time of day once the baby gets here at all 😑😑😑 she's gonna scare the shit out of him and if he's sleeping; I know for a fact that she's gonna wake him up crying. 

What can I do to try to control her behavior? I'm at my wits end.