An online service stores and augments aggregated content that is obtained from different content sources. For example, the content may include electronic messages, calendars, contacts, social network content, feed data, search results, and the like. The online service augments the aggregated content to include additional content. The online service may augment the aggregated content differently based on the type of the content being augmented. For example, electronic messages may be augmented differently as compared to when augmenting calendar events or contact cards. Searches may be made across all or a portion of the different content sources that are aggregated and augmented for a user. For example, a user may view the messages from a particular user regardless of the message provider providing the content to the user. Similarly, a user may perform a general search across each of the different content sources to locate items matching a search query.