I got an email that includes a PGP signature as .asc.
As far as I understood, it ensures, that the email is really from the sender and it should be possible to decrypt the signature with his public key.
I try to use gpg to do that. But the documentation says, that I will need also the document for what the signature is for to verify. So I can not find a command example for what I am trying to do. I read for example this documentation https://www.gnupg.org/gph/en/manual/x135.html
Did I mix something up? If I will really need to give the email content to the command too, it will be hard to decide, which parts of the email I will need and in which format I will have to put it to the gpg invocation.