Yes, you can use GIFs in your email templates.
The maximum size for GIFs is 1MB.
Loading time speed
The following may impact the loading speed of your GIFs:
- Image size
- Number of frames
- Number of colours used.
You can reduce GIF size by adjusting the colour settings on export and setting dithering etc., which will reduce the file size.
This can be done in photoshop or other graphic design tools like ezgif.com