To ensure emails containing images sent from Cerkl Broadcast are automatically downloaded within your Subscribers' inbox, have your technical team configure your email provider and corresponding admin systems to allow "Auto Download of Images" via "Safe Senders" lists.
This can potentially be accomplished by manipulating the "Safe Senders" list on each individual subscribers Outlook account to include either the overall company domain or specific email addresses that your communicators will be sending from, either by managing group policy pushes to individual machines or including these safe senders in the in the image for each new subscribers configuration.
Also, at the company level, in order to avoid applying this changes individually in each of the employee's PCs, the IT team can apply a Group Policy, in case the email client is Outlook, some resources in this area can be found here.