Transferring Delta SkyMiles to another comes with a price of $0.01 per mile. So transferring 1,000 miles will cost you $10. You must transfer a minimum of 1,000 SkyMiles and can only transfer a maximum of 30,000 SkyMiles per transaction. Up to four recipients may be included in a single transaction. There is also a $30.00 processing fee per transaction. Note: SkyMiles transferred into an account do not qualify toward Medallion Status.
In addition to the transaction minimums and maximums, there are also yearly maximum rules. The maximum allowed mileage deposited to a SkyMiles account per year is 300,000 miles and the maximum mileage transferred out of a SkyMiles account per year is 150,000 miles.