Check's in the mail phone number

The classic phrase!

The "checks in the mail" phrase is often used to express skepticism or frustration when someone says they will send payment or compensation, but it's unclear when or if it will actually arrive.

As for the phone number, I'm assuming you're looking for a contact number for a specific company or organization that has promised to send you a check. Can you please provide more context or information about who you're trying to contact? I'd be happy to help you find the correct phone number or provide guidance on how to follow up on your payment.