Email Bounce Address

That seems to be the configured SMTP server by your hosting. It might be possible to configure this if you have CPANEL included. If that’s the case, take a look at this article. It explains how you can create your own SMTP address and use it for sending e-mails from your website.

Alternatively, you can use another provider to send emails for you. I can recommend sending your emails with a SMTP provider like Sendgrid. You will need to signup, add CNAME records to your domain, and you can use for example mailing.example.com as your sender address. It offers a ton of features and Deliverability is great. With a plugin such as Post SMTP Mailer/Log this can be easily configured.

Let me know if it helps you!
Cheers..