But when they start saying you have to send $$ out of the country, because they're missionaries doing "god's work", and they'll mail you the keys....RUN. Classic scam.
Only deal with people IN PERSON -- preferably a property management company. If you're dealing with an owner directly, ask to see ID, and look up the property address in public records to make sure they are indeed the owner. Also...Ask a Realtor if the house is listed for sale in the MLS (most of the time it is) which is another red flag.
If it sounds too good to be true, it is.