An electronic mail such as a remind mail is sent at a timing which encourages bidding on an auction to apply to purchase a product. An electronic mail sending device sends a first electronic mail which notifies a user of a terminal device of a first application deadline in a transaction for which the first application deadline to purchase a product is set, and which includes link information to a webpage which lists information about the product to be traded, decides whether or not the application information is received by the first application deadline, compares the access time to the webpage and the reference time, and when the access time comes later than the reference time, makes a relative send time of a second electronic mail to be sent next come earlier than a relative send time of the first electronic mail which has already been sent.