I want new emails I open to always send from a specific email address!
When you compose a new email in Mac Mail you might notice that the "from" field is already filled in, and not always with the correct email address.
But, you can make sure to set a specific email address to always be the default "from" email.
Go to Mail>>Preferences and open the Composing option from the pop-up.
You'll see the option for Send new message from: with a dropdown to select which email address you'd like set for the default.
Voilà! All new emails will then be composed and automatically set to send from your specified email address.