You are right, Ian, a virus could be in an attached executable (.exe) file.
But it is nothing more than data until your computer actually runs it AS an
executable file. A virus can't infect your computer without being run by your
computer. So, yes, you can receive a virus through your e-mail, but it will
be completely dormant until it is run as an executable program. You can
examine the virus with various software programs and figure out its exact
sequence of 1's and 0's, but until you actually RUN the thing, it is
completely harmless.
- David Musick