How do I know if my holiday rental is legit?

I'm considering renting an apartment in Port de Pollenca, Mallorca for a month.  I first contacted a private owner who had advertised on eBay, but her apartment is not available for the dates I want.  She passed me on to the owner of a neighbouring apartment which is available.  The apartment looks great and the price is okay.  I know the town, so know exactly where the apartment is.  But before committing, is there any way I can confirm this is a legitimate rental and not a scam? 

Jackie

The problem is you DONT know until you get THERE you can only really do YOUR OWN due DILLEGENCE my advice book through A RECOGNISED website such as HOLIDAY LETTINGS  they carry an INSURED facility that if it does turn out to be BOGUS you are covered

Rod

I would also see if they have an advert on a big site and if they have been advertising for several years.  That is a pretty good precaution, as if there had been a big complaint - like the house didn't exist and it was a fraud - then they would have taken them off the site.

Thanks for the replies.  Decided to err on the side of caution and book in an "aparthotel" we already know.  While we're there we can try to check out the other apartment and maybe book for next time.

Jackie