You can easily reply to emails within Loop. Whether it's an email that's in your personal inbox, a Shared Inbox or a Team the process is the same.
Once you've opened an email you'll see 'Write a reply' at the bottom.
Click on 'Write a reply' and a blank email will open for you start replying.
Go ahead and write your email. If you need to, you can attach a file(s), add a signature, edit the font and style of the email or input a canned response.
Once you've written your email click on the blue 'Reply' button to send the email to the recipient.