If you need to send someone money, there is no reason to send them a check. Most banks will send money (for free) to any recipient who has an email address or cellphone number. If your bank won't, PayPal will. Setting up a PayPal account is free and easy and sending money is free and easy (you can do it by computer or by app). And unlike a mailed check that will take days to get there if at all, the money will be "delivered" within minutes if not sooner, and not get lost in the mail.
Link to PayPal Website