21. The method of claim 2 , wherein the set of information pertaining to the received electronic message comprises a sequence indicator that indicates an order in which the received electronic message was sent in the electronic message conversation relative to other electronic messages in the electronic message conversation, and wherein determining whether the electronic message conversation data structure is missing information pertaining to the prior electronic message comprises: deriving, based at least partially upon the sequence indicator, a target sequence indicator that precedes the sequence indicator; and determining whether the electronic message conversation data structure is missing a set of information, pertaining to the prior electronic message, that includes the target sequence indicator.
21. The method of claim 2 , wherein the set of information pertaining to the received electronic message comprises a sequence indicator that indicates an order in which the received electronic message was sent in the electronic message conversation relative to other electronic messages in the electronic message conversation, and wherein determining whether the electronic message conversation data structure is missing information pertaining to the prior electronic message comprises: deriving, based at least partially upon the sequence indicator, a target sequence indicator that precedes the sequence indicator; and determining whether the electronic message conversation data structure is missing a set of information, pertaining to the prior electronic message, that includes the target sequence indicator. 22. The method of claim 21 , wherein the sequence indicator comprises a first sequence number, and wherein the target sequence indicator comprises a second sequence number that precedes the first sequence number.