Unfortunately, you can't directly respond to someone who has sent you a message or file through your Secure Deposit Box because Secure Deposit Box channels are meant to be used for one-way communication and so you will be the only person in the channel (as shown below).

However, if the sender has provided their email address when sending you a file through your Secure Deposit Box (shown below), you may copy and paste their email address to add them as a contact in the channel and send them a message accordingly.

To see how to add a contact to a channel, please refer to this support article here.

Did this answer your question?