The message body in ONEiO is stored for 30 days. The same applies for attachments and raw messages.
The conversation attributes and message headers (such as ticket IDs, timestamps and message types) are kept until the ticket conversation has not received any new messages within the time frame of 1 year.
If the conversation in ONEiO has not been touched for 1 year that data is then removed from ONEiO.
If a situation occurs that a ticket is still open in either system, and there is an update to the ticket after 1 year, this is recognized by ONEiO as a New Ticket, triggering a New conversation.