Opening video attachment in Apple Mail

tallsweet wrote:

I can open video on my iPhone, but not my MacBook running iOs 10.15 The attachment in the email shows a triangle with a line through it.

//:0

Then it has not downloaded properly on the mac or corrupt in some fashion.

Try sending a known good copy to yourself as a test.

if no resolve Call (800) MY–APPLE (800–692–7753)

or on line https://getsupport.apple.com/