This feature, which is a way you can target a list of clients and send bulk emails, will be discontinued in Flybook on December 26th 2018.
In light of increasing consumer protections and regulations surrounding privacy, The Flybook wants to ensure you’re covered. Subscribing to an email marketing service who specializes in this field is in both you and your client’s best interest.

We’ve listed alternative service options for you below that offer great email marketing capabilities to enhance your campaigns. We also provide integrations with some, so that your lists are automatically updated when a new client is added into Flybook.
EMAIL SERVICES:
Mailchimp ($$$) https://mailchimp.com
Constant Contact ($$$) https://www.
SendPulse ($$ has a great pay as you go option!) https://sendpulse.com
MailGet ($) https://www.formget.com/