A method for processing security communication protocol compliant signed receipts at a mobile communication device linked to a host system is provided. The host system receives an email message linked to a digital signature, and a signed receipt. The host system redirects the signed receipt to the mobile communication device. The host system determines if the email message is available at the mobile communication device, and if not, the host system retrieves the email message and redirects the email message to the mobile communication device. The mobile communication device can then verify the signed receipt based on the email message. Optionally, rather than the email message, the host system retrieves and/or recalculates data elements associated with the email message and required to verify the signed receipt, and redirects these data elements to the mobile communication device. A related system is provided, as well as server computer program for the host system, and device computer program for the mobile communication device.