Hi @boknows1355! Great question, but my answer might vary as I don't understand the full question here. I will use a copier as an example since they have scan to email functions. If you set up that copier with smtp2go, mailgun or something similar, you are using those systems to send out the email since you already did the configuration for that system to allow sending as your domain. These systems essentially 'spoof' the sender and domain, so they do not have to be a legitimate mailbox, since the service is doing the heavy lifting and will require that the domain is the same as what you configured that system with. Some other platforms REQUIRE a mailbox to send emails so in those cases, yes they do have to be a real email address and mailbox.