References specific header in the collection.
The Item Property syntax has these parts:
evaluating to an object of type Pop3Hdrs.
||Required. A Variant
value. Index of the header, of string expression as
Item property is used to access specific header in the
collection of all headers that exist in email message.
Index parameter can be either integer value, in which case
it's between 0 and Count-1, and it
represents absolute header index in the collection. Also,
it can be string expression that represent header name,
such as 'From', or 'To' or similar.
If no such header exist, error is returned. String
expression is case insensitive.