FollowUpThen is a super simple email reminder service, and works wonderfully alongside Help Scout. All you need to do is add a specific FollowUpThen email address to the Cc or Bcc fields when replying to a conversation. This integration doesn't require installation within Help Scout.
How it works
When replying to a conversation, drop in a time-based FollowUpThen email address in to the Cc or Bcc fields. In our example below, we're adding firstname.lastname@example.org to the Bcc field, which will trigger a reminder in 5 minutes. Check out this page for more information on supported time formats.
Looking at the reminder
When the reminder expires, FollowUpThen sends a quick email that includes a couple of action links. If you choose to postpone the reminder, FollowUpThen will send another email based on the time period you selected. Help Scout will process the reminder email as a note, which will also set the conversation status to Active again.