A relatively old professor from another institute "forwarded" to me, using his work email, a work-related message he had received on his Gmail account.
However, he actually saved the entire Gmail webpage and attached it. A saved Gmail webpage may contain personal information and should not be shared with others.
He is based in a distant city and I didn't meet him in person (yet), but we work remotely on the same project.
Should I care and tell him about this bad security practice? How?