I keep more than your skin safe. 😃
This one was a bit trickier due to the lack description.
I first went to chat gpt and asked for a list of things that keep emails safe
Then i asked for a list of things that keep skin safe.
From that i saw that the spf for skin and the spf for emails had the same acronyms.
I checked it out and spf was the answer.
spf = sender policy framework