Out of curiosity, would you explain what you mean by that? Google was founded in 1998 and writing a mail client isn't terribly complicated. Did they buy some code for Gmail from an older company? Is Gmail older than Google?
> Did they buy some code for Gmail from an older company?
They bought both Deja and Neotonic.
A full featured mailed client is insanely complicated. If you think mail client is just smtp, you probably think word is just text with some styling and excel is just some cells and functions.