CHECK IS IN MAIL
I am in receipt of [SOURCE, ex. your payment request letter of June 10, 1998]. I have looked through our records and determined that our check #[CHECK NUMBER] in the amount of $[AMOUNT] was sent to you on [DATE, ex. June 5, 1998]. If you do not receive this check by [DATE, ex. the end of this week], please contact me and I will immediately forward a replacement check to you.