Using Classic Outlook on Windows for personal email, calendar, and contact management
Hello Katherine,
thank you for trying to help.
This seems to be an intermittent issue. I currently am not able to reproduce the issue.
Yet, when I analyze the e-mail I sent, I notice that it was saved in JPG format.
So, there is some circumstance causing Outlook to convert an animated GIF file into a JPG file when embedding the file into the message (Menu: Insert > Pictures). Probably Outlook converts the file silently when the overal message size, incl. attachments, goes beyond a certain level, but that's just an assumption of mine.
Anyway, Outlook should not silently convert the data type of images without prompting for confirmation.