New-mail notifications on your phone have buttons, so you can deal with an email without opening Newton. They work even when Newton is closed.
Steps
iPhone & iPad
Touch and hold a new-mail notification from Newton.
Tap Archive, Mark as read, Reply or Trash.
For Reply, type your reply and tap Send.
Android
Expand a new-mail notification from Newton to show its buttons.
Tap Archive, Mark as read or Reply.
For Reply, type your reply in the notification and send it.
Good to know
The notification goes away when you act on it, and Newton clears it from your other devices too.
Quick replies are plain: no quoted email, signature or attachments. Open the email to write a full reply.
For Gmail and Outlook, the button acts on the whole conversation. For IMAP accounts such as iCloud or Yahoo, it acts on that one email.
If an action fails, you'll get an Action failed notification. Tap it to open the conversation and try again. After a reply, check the conversation first, because it may have been sent.