Generally speaking the email address of the CEO of most corporations can be found online. All you need to do is Google the person's name + "email address". In the case of SPMarriott the CEO is Arne Sorenson. N.B. these email addresses are usually not read by the CEO themselves but their Executive Assistants who are empowered to take action on behalf of the CEO in these instances (generally have more authority than a Hotel Manager or Regional Manager of SPMarriott). In the rare instance that the EA feels this is a bigger F up than normal, they will in fact forward it on to the CEO as their job is also to act as a gate keeper between the general public and their precious CEO.

Safe Travels,

James