Can’t change sender’s name

Hello,

I created a newsletter and changed the sender’s name under: Settings/Basics/Default sender From and Reply to options, I also changed the same From and Reply to options when I’m ready to send the newsletter and click NEXT button (I didn’t send it, just saved the draft.) I sent several tests to my email, but I get the same original name, which is my first and last name, but I want to change it as a collaboration including another friend. I’m using the latest WordPress and MailPoet versions, no other plugins except Google Analytics, and using Storefront as my current theme. Please help, thank you.

Regards,

Aldo