How to Create Multiple ******@domain.com Emails?

Question

Hi, I'm having trouble creating multiple email address for different domains with 'info@'. So far, I was able to create a shared mailbox of ******@example1.com, but I would like to use a different domain name of ******@example2.com. How would this be accomplished? Whenever I try creating an info@ email address I receive this error message:

Email address not available because it's used by example1.

Ultimately, I am wanting to have 3 info@ email address to place in our websites. This would only be used for incoming support emails.

1. ******@example1.com
2. ******@example2.com
3. ******@example3.com