9. A system including memory and one or more processors operable to execute instructions stored in the memory, comprising instructions to: group a corpus of outgoing communications sent by a user into a plurality of clusters, wherein each outgoing communication of the corpus is grouped into a cluster based on one or more attributes of a recipient to which the outgoing communication was sent; classify one or more segments of each communication of a particular cluster as fixed in response to a determination that a count of occurrences of the one or more segments across the particular cluster satisfies a criterion; classify one or more remaining segments of each communication of the particular cluster as transient; generate, based on sequences of classified segments associated with each communication of the particular cluster, an outgoing communication template that is usable to automatically populate at least a portion of one or more draft outgoing communications; determine, based on one or more interactions between the user and a computing device operated by the user, that the user is preparing a subsequent outgoing communication; select a particular outgoing communication template from a plurality of outgoing communication templates, wherein the selecting is based on a measure of similarity between the particular outgoing communication template and the subsequent outgoing communication being prepared by the user; and apply the particular outgoing communication template to automatically populate at least a portion of the subsequent outgoing communication being prepared by the user with content from the particular outgoing communication template.
9. A system including memory and one or more processors operable to execute instructions stored in the memory, comprising instructions to: group a corpus of outgoing communications sent by a user into a plurality of clusters, wherein each outgoing communication of the corpus is grouped into a cluster based on one or more attributes of a recipient to which the outgoing communication was sent; classify one or more segments of each communication of a particular cluster as fixed in response to a determination that a count of occurrences of the one or more segments across the particular cluster satisfies a criterion; classify one or more remaining segments of each communication of the particular cluster as transient; generate, based on sequences of classified segments associated with each communication of the particular cluster, an outgoing communication template that is usable to automatically populate at least a portion of one or more draft outgoing communications; determine, based on one or more interactions between the user and a computing device operated by the user, that the user is preparing a subsequent outgoing communication; select a particular outgoing communication template from a plurality of outgoing communication templates, wherein the selecting is based on a measure of similarity between the particular outgoing communication template and the subsequent outgoing communication being prepared by the user; and apply the particular outgoing communication template to automatically populate at least a portion of the subsequent outgoing communication being prepared by the user with content from the particular outgoing communication template. 10. The system of claim 9 , wherein the corpus includes outgoing communications sent by one or more additional users, and wherein each outgoing communication of the corpus is grouped into a cluster based on one or more attributes of a context of a user that sent the outgoing communication.