[minimaul]

It's not just the use of @gmail.com, it's the fact that it's clearly an autogenerated address with random chars that tripped me.

If it was claiming to be a small business from [e-mail], I'd be less suspicious - but a large corporate not using their own domain for mail, the email address itself, and the then switching to a second email address are all giant red flags for me.

[bitcharmer]

Exactly this. How these email addresses didn't raise any red flags is beyond me.

Looks like many people are much more gullible than I ever imagined.