envoy/src/main/resources/message_schema.xsd

<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
	targetNamespace="https://github.com/informatik-ag-ngl"
	xmlns="https://github.com/informatik-ag-ngl"
	elementFormDefault="qualified">

	<xs:element name="Message">
		<xs:complexType>
			<xs:sequence>
				<xs:element name="MetaData">
					<xs:complexType>
						<xs:sequence>
							<xs:element name="Sender" type="xs:string" />
							<xs:element name="Recipient" type="xs:string" />
							<xs:element name="Date" type="xs:date" />
							<xs:element name="State" type="xs:boolean" />
						</xs:sequence>
					</xs:complexType>
				</xs:element>
				<xs:element name="Content" maxOccurs="unbounded">
					<xs:complexType>
						<xs:sequence>
							<xs:element name="text" type="xs:string"/>
						</xs:sequence>
						<xs:attribute name="type" type="xs:string" />
					</xs:complexType>
				</xs:element>
			</xs:sequence>
		</xs:complexType>
	</xs:element>

</xs:schema>