I just have to quote the email received last night which is a fine illustration of how grandiose those crackpots can be:
SUBJECT: An oldest & excellent wall clock for sale
Sir,
I want to sale an oldest and excellent wall clock. It was made on those days when trade-mark was not necessary. There is no trade-mark on this clock. No confirmation where it was made. Yet the condition is good. It has English & Roman numerals, alarm & bell. Size of clock is 19 x 10 x 4 inch with wooden box.
It costs US$ 500,000.00 ( Five hundred thousand US Dollar ). If you are interested to buy it, please contact me. Image enclosed. Thanks.
Sincerely,
XXX


Obviously, there is some entertainment value to this email. However, I've yet to find out any other reason to waste my time explaining to the "seller" that his clock is neither rare nor fine: as a matter of fact, one can buy truckloads of common American kitchen clocks on Ebay for $10 at any given day of the year.
If I really had to send a reply to this "seller", it would look like this:
...
I want to sale an oldest and excellent wall clock (It is really a mantel clock). It was made on those days when trade-mark was not necessary (no, it was not. It was made in 1880s). There is no trade-mark on this clock (yes there is - it is located on back plate of the clock movement). No confirmation where it was made (somewhere on the East coast of US, most likely NY). Yet the condition is good (unfortunately the condition is way below average). It has English & Roman numerals (no, it has Arabic numerals), alarm & bell. Size of clock is 19 x 10 x 4 inch with wooden box (the wooden box IS the clock).
It costs US$ 500,000.00 ( Five hundred thousand US Dollar ) (it is really worth $20). If you are interested to buy it, please contact me (no I won't). Image enclosed. Thanks.
...
Can anyone recommend a good junk mail filter please?