Magento Cloud – How does SendGrid send email with sender “[email protected]”?

Hi everyone,

I have not much experience with Email sending things. I have a Magento Cloud instance(vanilla), I saw email is sending out with sender like: [email protected], and [[email protected]](mailto:[email protected])…

I tried to replace it with a dummy email address, it also send emails with sender as dummy email address.

I wonder how it works? could you share keywords/info so that I can search google more accurately?

What if I try to configure it with a big brand email domain like: [[email protected]](mailto:[email protected]), [[email protected]](mailto:[email protected])? will that also work? Sorry I can’t try on this Magento Cloud instance, because it’s from my Client.