I'm building a tool in which I need to send more than 2 messages in the same thread (the message have identical subject & recipients) using Microsoft Graph API with some interval of days between them.

The problem is that I cannot send a message in the same thread using the API, even though the subject & recipients are same, Outlook displays them as different threads (but on the recipients' side (Gmail side) - they belong to same thread).

I tried using conversationId (which I got in the first message) in the second message but they still ended up showing in different threads.

Is there any way in I can send messages in the same thread?