Did you interview for the role?

If not, then it's a fake.

Did you apply for the role?

If not, then it's a fake.

Have they flown you to Doha to meet with several members of the executive team? (For senior level roles)

If not, then it's a fake.

For mid level roles and above, telephone interviews, face to face interviews, and CV submitted directly by you are mandatory. They're pretty common for lower level roles as well, but not always.

If it seems to be too good to be true, IT IS.