Abstract: Systems and methods are disclosed that facilitate identifying messages generated on a mobile device while the device is offline as requiring encryption, storing the messages in a message outbox with a flag indicating that encryption is required, and identifying recipients of the flagged messages to generate a recipient list. The recipient list can be piggybacked on a server synchronization request when the mobile device enters a period of online activity, and a server can return public keys associated with identified recipients to permit an encryption component, such as a secure/multipurpose Internet mail extension protocol (S/MIME) encryption component, in the mobile device to encrypt the messages.

Abstract: Systems and methods are disclosed that facilitate identifying messages generated on a mobile device while the device is offline as requiring encryption, storing the messages in a message outbox with a flag indicating that encryption is required, and identifying recipients of the flagged messages to generate a recipient list. The recipient list can be piggybacked on a server synchronization request when the mobile device enters a period of online activity, and a server can return public keys associated with identified recipients to permit an encryption component, such as a secure/multipurpose Internet mail extension protocol (S/MIME) encryption component, in the mobile device to encrypt the messages.

Abstract: Systems and methods are disclosed that facilitate identifying messages generated on a mobile device while the device is offline as requiring encryption, storing the messages in a message outbox with a flag indicating that encryption is required, and identifying recipients of the flagged messages to generate a recipient list. The recipient list can be piggybacked on a server synchronization request when the mobile device enters a period of online activity, and a server can return public keys associated with identified recipients to permit an encryption component, such as a secure/multipurpose Internet mail extension protocol (S/MIME) encryption component, in the mobile device to encrypt the messages.

Abstract: Unsent messages are securely stored in a client by determining whether a connection to a server exists. If the connection exists, the message can be sent using the intended recipient's public key. In response to a determination that a connection from the client to a server does not exist, information from the client can be used to encrypt a modulated data signal that is to be sent from the client to the server. The encrypted modulated data signal is stored on the client. When a determination is made that a connection from the client to the server exists, information from the client is used to decrypt the encrypted modulated data signal.