add to API response fields which represents Thread topic ID to build rich email clients
New attributes for a message in response:
- threadTopicId - value will contain Reference header if exists in email,
if Reference does not exists in email headers , than value will be the same as In-Reply-To header. If there are no Reference and IN-Reply-To header's in email - Message ID will be used.
- reference - represents Reference header item (can be null)
- inReplyTo - represents In-Reply-To header item (can be null).