Gifs are supported in HubSpot's editors; however, they are not supported in every email client. For example, both Outlook and Gmail do not always support gifs (see articles below):
Hi. I just had this problem and thought I would share at least the solution that worked for me. When you go to insert the photo (GIF) instead of selecting "upload files" select "from URL" and then link the GIF you want. You can create a link to your GIF a bunch of different ways, I used Giphy (It's free).
Gifs are supported in HubSpot's editors; however, they are not supported in every email client. For example, both Outlook and Gmail do not always support gifs (see articles below):