Selecting a source account for an outgoing communication content of a user is described. A collection of source accounts is associated with the user. Each source account has an individual content storage storing communication content associated with the corresponding source account. A user's authentication is validated for using the collection of source accounts. One source account in the collection is designated as a primary source account. The source accounts in the collection are aggregated to a primary content storage. The user is authenticated to sign in to the primary source account. Instructions are received from the user for generating a communication content from the primary source account and the primary content storage. Instructions are received from the user for selecting one of the source accounts in the collection as the source account for the generated communication content, and the user is signed in to the primary source account.