in mail-archive/server/src/main/java/org/apache/sling/mailarchiveserver/impl/MessageStoreImpl.java [262:278]
static Map<String, Object> getMessagePropertiesFromHeader(Header hdr) {
Map<String, Object> props = new HashMap<String, Object>();
parseHeaderToProps(hdr, props);
// message name
String name;
if (hdr.getField("Message-ID") != null) {
name = hdr.getField("Message-ID").getBody();
name = name.substring(1, name.length()-1); // remove < and >
} else {
name = Integer.toHexString(hdr.getField("Date").hashCode());
}
props.put(MessageFieldName.NAME, name);
return props;
}