Among all the Exchange Web Services Operations I'm looking for the simplest one I can initially use to check if my connectivity to the EWS endpoint works.
The low-level code I use to build and execute SOAP calls expects valid results so whatever operation I use should not return with an error message.
I have considered several but don't find them satisfactory:
GetServerTimeZones is only supported from Exchange 2010, and I need 2007+
ResolveNames needs a (partial) user name, but I want it do to be user independent. Also, it could return errors (not match) or maybe hundreds of matches (match with 'e').
GetUserConfiguration works for the currently logged in user, but is only supported from 2010.
Any other ideas?