I have to add values to some outlook contact fields using EWS. I've managed to do that with the 'User Field 1' using this article . The problem is that i need to insert values in other fields (for instance 'Account' in 'Miscellaneous Fields') and I need to know the id of these properties. Here is the code i'm using to create the property, i need to set the second parameter:
Guid myGuid = new Guid("{00062004-0000-0000-C000-000000000046}");
ExtendedPropertyDefinition myDef = new ExtendedPropertyDefinition(myGuid, 0x804F, MapiPropertyType.String);