Many email service providers have implemented new restrictive policies on emails that are sent from a person's account (e.g., Yahoo.com) but did not originate from their email server. Because Rock sends email on behalf of others these emails can bounce in these situations. To prevent this, if an email communication is created with a From Address that is not in the Safe Sender Domains defined type, the Organization Email global attribute value will be used instead for the From Address and the original value will be used as the Reply To address.

You'll want to add all of your organization's email domains to the Safe Sender Domains defined type under: Admin Tools > Settings > Safe Sender Domains