An electronic mail wrong transmission determination apparatus includes: a feature information creation unit which creates feature information related to contents of an electronic mail that is a transmission object; an accumulation unit which accumulates feature information related to contents of a transmitted electronic mail and a destination of the transmitted electronic mail in association with each other; a destination candidate selection unit which selects destination candidates that are similar in appearance to a destination of the electronic mail that is the transmission object, from destinations of transmitted electronic mails; a similarity model creation unit which creates a similarity model for each destination accumulated in the accumulation unit based on the feature information accumulated in the accumulation unit in association with the destination and based on the feature information accumulated in the accumulation unit in association with other destinations that differ from the destination; wher
