When you start sending using our API, the only domain you can use is our default cmemailcampaigns.com domain. If you want to use your own domain to send email, you have to verify your domain. In order to do so you'll have to create a few DNS entries. These DNS records are necessary to let mailboxproviders know that the mail is really coming from you. This seems like a lot of work to start with but unfortunately, it's really necessary. If we would let you send without the domain verification, a lot of your email would be blocked or end up in the spam folder.
When your domain is verified, you can use every email address you want without further verification mails. So if you verified myawesomecompany.com you can send from all these addresses: