Hotmail - suddenly sending all black page

I’ve had this hotmail for decades. Sent three msgs tonight and recips all replied they got a solid black page.

But it looks fine to me, AND, their replies also look okay.

So, I can see my mail, but they can’t, and when they reply, I can still se my original.

Never encountered this before.

opinions?

Are all of the recipients using a specific email system ie. Gmail, Hotmail/Outlook/Live, security app or browser, if using other web-based Gmail accts?
Were the messages forwards or include an image possibly?

Just sent a test message from a Hotmail acct to 3 different Gmail accts and an USPS acct. No issues.

The first event was a forward from one friend to another. She said, “all black”

So I copied the original mail and generated / pasted a new email to the same friend. She replied, same thing, all black.

Same thing when I merely replied to a friend’s mail with just a few words. She said, all black.

I used chrome but have since tried gmail and edge, no replies yet