Total costs X Company?

$10,326 of the computer hardware costs were common costs that will continue even if the email system is abandoned, and X Company will still need to pay for the virus protection license. Y Company has offered to operate an email system for X Company for $11.10 per mailbox. Next year, X Company estimates that 4,190 mailboxes will be required per month. By how much will X Company's monthly profits change if they decide to outsource its email function to Y Company instead of managing the service internally? [A positive number means that make costs are more than buy costs; a negative number means that make costs are less than the buy costs.]