Start Internal Conversation With details is not capturing the email replies.

We have configured a channel under 'Collaboration' Purpose for the email based reply for conversation so in all the scenarios it is working fine it is capturing the email based replies under the same thread of the conversation of the HRHD but when i am trying with 'start internal conversation with details' and here when i am trying to include the Message , then it is not working for email replies, i am replying through an email but it is not capturing that in the same conversation thread of the HRHD page.

because when i am creating the conversation by including messages it is sending an email like including the tag #number from the message and also taking the tag #number from the conversation.