One or more computing devices, systems, and/or methods for auto-generating subject suggestions are provided. For example, a set of n-grams are generated from text within an email body of an email being composed by a user and/or from descriptive information of attachments to the email. Features of the set of n-grams are identified, such as a date feature, a proper noun feature, an activity feature, a number of words feature, etc. Classifiers are used to assign probabilities to the n-grams based upon the features. A probability may specify a strength of an n-gram in relation to a user preference of the user for an email subject derived from the n-gram. In this way, an email subject suggestion is generated based upon a target n-gram with a probability exceeding a threshold. The email subject suggestion is provided to the user, such as during email composition or during sending of the email.