From routesonline:
Approximately from 04SEP17, planned new codeshare routes as follow.
AeroMexico operated by DELTA
Atlanta – Birmingham AL
Atlanta – Charlotte
Atlanta – Dayton
Atlanta – Ft. Lauderdale
Atlanta – Grand Rapids
Atlanta – Louisville
Atlanta – Norfolk
Atlanta – Omaha
Atlanta – Providence
Atlanta – San Juan
Detroit – Baltimore/Washington
Detroit – Boston
Detroit – Cleveland
Detroit – Grand Rapids
Detroit – Hartford
Detroit – Newark
Detroit – New York JFK
Detroit – New York LaGuardia
Detroit – Philadelphia
Detroit – Pittsburgh
Detroit – Washington Reagan
Los Angeles – Las Vegas
Los Angeles – San Francisco