you can email me direcly by using the email address that is displayed when you click on my name in the "posted by" header to the forum message. Note that email addresses shown that way are displayed in a graphical form to prevent spammers from picking up email addresses from the forums.
the source of DNA that is most useful to genealogy is the Y-chromosome, which is passed from father to son essentially unchanged generation after generation. Every son has his father's Y-chromosome and two distant cousins seperated by many genetations will have similar Y-DNA as long as both are descended through a totally male-to-male line from a common male ancestor. A female does not have a Y-chromosome: in fact, having a Y-chromosome is what causes an embrio to develope into a male and not having a Y-chromosome causes an embrio to develope into a female.
The passing of the Y-chromosome from father to son is "essentially" without change, but not perfectly so; there are small changes due to random mutations, which are rare. Typically, the DNA between two 10th cousins might be 95% the same and 5% different due to the rare mutations. The rate of mutations is "just right"; if the rate was a lot faster, the DNA would not remember our ancestors long enouth to be usefull; and if it was a lot slower, we would all have DNA so similar you would not be able to tell us apart.