Taxonomies, this and that

[Thomas Schlemmermeyer]

Hello, I am Thomas, and I would like to put the following questions:

1.) a rather practical one, concerning taxonomies of e-mail messages:
It often occurs that I am receiving e-mail messages with strange and
unsolicited contents. How do I have to proceed to classify these messages and
how can I know more about the strange senders?

2.) a more esotherical one: Now they are looking for signs of extraterrestrial
intelligence in the universe. More specifically, scientists are screening the
universe for meaningful laser- or radio messages.
Let us suppose that this search be successful. How these extraterrestrial
fossils would have to be dealt with taxonomically?

Sorry for my bad English,  best wishes,   Thomas