Is it ok to send cash ($100) through the mail or is it just a terrible, stupid idea?
If it’s to someone you know (and not someone that your concerned might claim they didn’t get it). I wouldn’t worry. Wrap it in something so you can’t see it if held to the light and mail it. IMO the only real risk is that it could get lost in the mail.
The latter… I mean, what could possibly go wrong? This is probably IMHO territory…
It’s only okay in the sense that it’s okay to lose $100 at the casino.
At the casino, you might get a couple of (watered-down) cocktails out of it though…
Seriously though, I dont think that I would mail cash, when there are so many other options available…
I’ve heard that some dishonest postal workers look for greeting cards in the mail and open them in the hopes of finding cash. (No cite, and I don’t mean to slight the employees of the USPS, whom I believe are largely honest.) So don’t put the money in a greeting card.
Don’t do it. I had a grandparent that did that for my birthdays. A large percentage of cards were received minus the cash after having been opened on the way.
I sent a payment to a credit card $75.00 in June 2008 and the credit card company never got it. It’s now half way through February 2009 and I STILL have yet to get a refund on the money order from the post office.
They keep “investigating it,” They can’t tell me if it was even cashed.
So from my point of view a money order is hardly any better if it gets lost. I wonder if I’ll ever see that money.
I go in once a month to a post office, I’ve been to several and I fill in a form with the number and the post office clerks tell me I should get a letter in the mail. Which I never do.
A friend worked for a time in the US Attorney’s office, and when you first start out, they assign you some of the smaller cases (you don’t start by, say, prosecuting a governor who’s trying to solicit bribes while being wiretapped). One of the crimes she prosecuted with relative frequency was interfering with the mail. I don’t recall its official name, but apparently it’s pretty common for people to take mail out of those outdoor mailboxes (gum on the end of a stick is a pretty popular tool) and open all the envelopes to see if there’s money in them.
So if you have some option other than cash, I’d use it.
As previously mentioned, if you are not sending it to a trustworthy party there could also be problems at the receiving end. Why do many companies specifically say “do not send cash”? It avoids the problem of light-fingered employees helping themselves to your payment.
I suspect as long as you wrap the money in some paper so it’s not at all visible through the envelope, and you send it in a regular envelope rather than a greeting card one, it should be fine. We get orders with cash every once in a while, nobody has ever contacted us and said they sent cash but it didn’t make it.
I wouldn’t do it. In the early 1970s I worked in a bank processing deposits mailed in. Even though there was a heavy paper folder with “Do Not Send Cash” printed prominently on it, some customers still mailed in cash. The majority of the time there was no cash in the envelope by the time we received it at the bank.
I wouldn’t send a postal money order either, for the reasons stated above. A personal check is much safer for you, if less convenient for the recipient.
But… But … Just read here on the SDMB. All people are basically good. Evil or bad people are very few and far between.
So if there are only 10,000 liars, cheats, thieves, killers, & what not in the country, well how many could work for the post office? Have a stick with gum and be near your mail box? Don’t you trust your fellow man? I have never lost cash in the mail. I have sent it probably 5 times in the 55 years I have been personally using the mail.
That settles it. Everyone on the SDMB is correct. There are very few bad people. Everyone is basically good. the very idea that one needs to assume that people are bad and not do something we have a right to do like sending $$$ in the mail is wrong, wrong, wrong…
Jeez folks … Pay attention… You claim that 99.9999999999% of people are good and then go and say to not send $$ in the mail because it might get stolen… Shame on you… 
It’s totally fine, as long as you get my address correct.
Don’t do it. The chances that it would be lost or stolen are small, but if it is lost or stolen you can’t even prove that you ever sent it, much less be able to trace and recover it. It will be gone forever. USPS highly discourages sending cash.
My mother sent me a Best Buy gift card for my birthday but all I got was an empty envelope. A postal worker was arrested after Best Buy had him on security video using the card.