Can I use CAYA on mobile devices? Mobile use of CAYA is easily possible with our app. Simply download it from the Apple App Store or Google Play Store and manage your mail even more flexibly! Mobile use in the browser of your cell phone is not supported by our platform. Related articles How can I order an immediate shipment? How do I log into my CAYA account? How can I download the CAYA app? What is a bundled delivery? What is the CAYA mailbox?