If the sender is included in the destination address, such as if the sender is included in the recipient's mailing list or BCC, the following tracking will not be performed.
・ Incoming receipts in the destination mailbox are not tracked
・ On the contrary, the sender's mailbox is tracked even though it is not a reply.

The senders are often included in the destination mailing list. We often share information with the same project members.
However, there is a risk of missing mail because the destination mailbox is not tracked.

Please improve the function so that the recipient's mailbox is tracked even if the sender's address is included in the recipient.