If you want to reply to a previous email, do the following:
1. Click on the Follow up button. You will find this inside the contact's profile page, or next to your follow-up suggestion.
2. Once the follow-up modal (compose window) is opened, you'll see previous emails on the right side of the modal under Recent Conversations. Hover your mouse to the email you want to reply to.
3. Once you hover over the email subject line, a Reply button will appear.
4. Click on Reply and you will see the email thread placed inside the message box.
5. Proceed typing your email message and Send
How do I send an email through Contactually?
How do I use Scale Mail?