1) Click Read the Message
2) Choose your option to sign in. For this exmaple we will use the One-Time Passcode
3) Check your email for the One-Time Passcode. Take note of the passcode as it will be needed to access the message.
4) Enter the One-Time Passcode and click continue
5) Read the context of the message and click reply or Reply all to compose your reply
6) Type your reply / Attach any documents / Click Send.