12. One or more non-transitory computer readable media having instructions thereon that, when executed by one or more processing devices of a computing device, cause the computing device to: receive a message addressed to a user; determine whether the received message has a theme that is similar to a theme of a message collection, comprising one or more previously detected messages including an index message wherein the message collection and the received message have a similar theme when the messages in the message collection have a common sender or have common content as the received message, and wherein the theme of the message collection is defined by a sender and a modality of the index message that is a first received message at a beginning of a predetermined window of time; identify a messaging modality associated with each of the messages in the message collection, wherein the messaging modality comprises a mode in which each of the messages in the message collection was sent including one of e-mail, social media, phone call, calendar invitation, text message, Internet service message, microblog message, chat message, or voicemail; determine whether the message collection satisfies modality criteria, wherein the modality criteria specify that at least two different messaging modalities be associated with messages in the message collection, wherein the at least two different messaging modalities comprise two or more of e-mail, social media messaging, phone, calendar invitations, text messaging, Internet service messaging, microblog messaging, chat messaging, and voicemail; and in response to a determination that the message collection has a similar theme and a determination that the message collection satisfies the modality criteria, provide a notification of the message collection.
12. One or more non-transitory computer readable media having instructions thereon that, when executed by one or more processing devices of a computing device, cause the computing device to: receive a message addressed to a user; determine whether the received message has a theme that is similar to a theme of a message collection, comprising one or more previously detected messages including an index message wherein the message collection and the received message have a similar theme when the messages in the message collection have a common sender or have common content as the received message, and wherein the theme of the message collection is defined by a sender and a modality of the index message that is a first received message at a beginning of a predetermined window of time; identify a messaging modality associated with each of the messages in the message collection, wherein the messaging modality comprises a mode in which each of the messages in the message collection was sent including one of e-mail, social media, phone call, calendar invitation, text message, Internet service message, microblog message, chat message, or voicemail; determine whether the message collection satisfies modality criteria, wherein the modality criteria specify that at least two different messaging modalities be associated with messages in the message collection, wherein the at least two different messaging modalities comprise two or more of e-mail, social media messaging, phone, calendar invitations, text messaging, Internet service messaging, microblog messaging, chat messaging, and voicemail; and in response to a determination that the message collection has a similar theme and a determination that the message collection satisfies the modality criteria, provide a notification of the message collection. 14. The one or more non-transitory computer readable media of claim 12 , wherein the computing device is a personal computing device associated with the user.