I mailed a card with money(I know, stupid...) to our son-in-law, from Webb City, MO, to...

I mailed a card with money(I know, stupid...) to our son-in-law, from Webb City, MO, to Basehor, KS last Tuesday, Oct *. I went to the P.O. counter to have them check if additional postage might be needed. I was told it needed **cents above the already attached stamp, and I paid and it was attached. The gentleman told me he would be sure to see that it got in "today's" mail, and kept the card. I hadnt expressed any need for urgency, but I certainly thought it should go out that day, since I was mailing it before noon, and the cutoff is late afternoon... so I wasnt sure why he felt he needed to say that, or why he didnt give me the card to put in the drop box, but I left.*Normal mail time between us and Kansas City*Basehor is * days. The letter didnt get there for * days, and it was opened, with no attempt to put the contents in plastic,as I have seen with compromised mail before. The money ($***) was gone. I had alerted our daughter that it was coming and she retrieved the mail as soon as it got there. She still has the card and envelope.*I realize probably nothing can be done about my problem, but I would like my post office to be aware that it was possibly the employee who took my card at the counter who might have taken the money. It was not originally an extra postage card, but we had a brief conversation about it being weighed since i had inserted something, and I'm thinking he might have deduced it was a gift card or money. There shouldnt have been a reason for the card to be opened: it was in pristine condition and normal thickness. Thank you for relaying this information to the Webb City, MO postmaster or responsible person there...