Communication systems and methods transfer information between a client device and a vendor device through a firewall between the client device and the vendor device by using a communications protocol that will normally allows pass through the firewall and/or by e embedding the information in a file format that will normally pass through the firewall. The information can be transmitted using the hypertext transfer protocol, and/or is embedded in an HTTP document or in an e-mail message. If the client device is on a secure side of the firewall and the vendor device needs to initiate communication with the client device, the vendor device can send an e-mail message to the client device asking the client device to initiate the communication session. Because the client device has initiated the communication, the firewall should allow the response to the client device's request to pass through from the vendor device to the client device.