I received an email saying they hoped I enjoyed my access to Delta Sky Clubs. I am a platinum american express delta card holder. Am I granted access to the sky clubs?

If you're not a member you have to pay $39. Members always have access.

No

Only the regular platinum Amex gives access to a delta lounges in U.S. while traveling on Delta. The reserve Delta Amex card gives access not the platinum Delta Amex!