If I win a sweepstakes prize, is it legal for them to ask me to send them money to receive my winnings?

I received a phone call saying that I have win a $325,000.00 prize from America Publishers sweepstakes. But in order to receive my winnings I would need to send them $595.00 for insurance and delivery. I should send the money through Western Union, to a Ruth Acosta at Santo, Dominican Republic. Is this a legal and proper procedure?