The client may request/send properties representing individual header fields of the form:
header:{header-field-name}
Where {header-field-name} means any series of one or more printable ASCII characters
(i.e., characters that have values between 33 and 126, inclusive), except for colon (:).
The property may also have the following suffixes:
:as{header-form} This means the value is in a parsed form, where
{header-form} is one of the parsed-form names:
Raw, Text, Addresses, GroupedAddresses, MessageIds, Date, URLs.
. If not given, the value is in Raw form.
:all This means the value is an array, with the items corresponding to each
instance of the header field, in the order they appear in the message.
If this suffix is not used, the result is the value of the last instance of
the header field (i.e., identical to the last item in the array if :all is used),
or null if none.
If both suffixes are used, they MUST be specified in the order above.
Header field names are matched case insensitively. The value is typed
according to the requested form or to an array of that type if :all is used.
If no header fields exist in the message with the requested name, the value
is null if fetching a single instance or an empty array if requesting :all.
The client may request/send properties representing individual header fields of the form:
header:{header-field-name}Where {header-field-name} means any series of one or more printable ASCII characters (i.e., characters that have values between 33 and 126, inclusive), except for colon (:). The property may also have the following suffixes:
:as{header-form} This means the value is in a parsed form, where {header-form} is one of the parsed-form names:
Raw,Text,Addresses,GroupedAddresses,MessageIds,Date,URLs. . If not given, the value is in Raw form.:all This means the value is an array, with the items corresponding to each instance of the header field, in the order they appear in the message. If this suffix is not used, the result is the value of the last instance of the header field (i.e., identical to the last item in the array if :all is used), or null if none.
If both suffixes are used, they MUST be specified in the order above. Header field names are matched case insensitively. The value is typed according to the requested form or to an array of that type if :all is used. If no header fields exist in the message with the requested name, the value is null if fetching a single instance or an empty array if requesting :all.