(1) The district court correctly granted summary judgment on breach of contract claim where email chain did not contain acceptance of offer and where partial performance exception to statute of frauds did not apply.
(2) The district court correctly granted summary judgment on promissory and equitable estoppel claims where email did not contain sufficiently clear and definite pricing formula upon which appellee should have expected appellant to rely and where equitable estoppel claim applies only in insurance coverage disputes.
(3) The district court erred in granting summary judgment on unjust enrichment claim where reasonable factfinder could find that appellant conferred benefit on appellees when they took his plans and design efforts without paying for them.