Yes. maileo is built around custom domain email, which means you use your own domain name for mailbox addresses such as you@yourdomain.com. The key requirement is that the domain's DNS must be configured correctly for the service.
Before switching live mail, make sure your domain is verified and that the required records are in place. A custom domain setup is only as reliable as its DNS configuration.
If you manage DNS elsewhere, that is fine as long as the required values are published correctly.