What happens if I include my 'signature' within the email?
When your email is received, it is searched for the first occurence of those values which are relevant to to the message and these are recognised as being the first word on an individual line.
As such, including your signature within the email makes no difference to the message sending process as it would be discarded. Even if a line within your signature began with a parameter's name, the signature would have to come first in the message for it to be acknowledged.