46. The memory device of claim 45 , wherein the operations further comprise: receiving a response to the request electronic message, the response including the prior electronic message that was requested in the request electronic message; obtaining a set of information pertaining to the prior electronic message; accessing the electronic message conversation data structure; and updating the electronic message conversation data structure to include the set of information pertaining to the prior electronic message, and to indicate that the response to the request electronic message has been received.
45. The memory device of claim 28 , wherein the operations further comprise: updating the electronic message conversation data structure to indicate that the request electronic message has been sent to request resending of the prior electronic message.