PoliteMail supports adding animated GIFs to Outlook emails, however, animated GIFs are not supported in Outlook 2007-2016. Here is a handy reference chart that shows which Email Clients support animated GIFs.
For Outlook 2007 - 2016 desktop recipients, the animated GIF will display the first image. Please note that OWA on the web (Office.com) will display the animated GIF. When creating the animated GIF, you will want to make the first frame something engaging that works on all viewing devices. Do not leave the first frame blank.
To add an animated GIF to a PoliteMail email, create the GIF animation and save it as a GIF.
Now go to Outlook > New Message> PoliteMail and choose Add Image. Navigate to your saved GIF file.
Your animated GIF will now be added to your message.
For Outlook 2007-2016 Desktop users, I have chosen the image of the angry email as my first frame of the GIF animation. All other users will see the full animated GIF of the envelop shaking and then opening happily.