2 points
Mine was like that too so I just deleted them and moved on. I sat right next to the security team and would thus know when they were going out, so they gave no shits as long as you didn’t fall for it.
It also helped that my team was the only in the company that didn’t really get email. Everyone else got hundreds a day (no joke, they used way too many mail lists) and we got maybe 5-10, all internal or auto-generated, so everything was super obvious, and IT was well aware of this.