For those of you that don't understand what a rebuttable presumption is as it is understood in the realm of jurisprudence, allow me to give you an example. You are a married male and your wife gets pregnant and gives birth to a child. You know with absolute certainty that you're not the childs father because 1)You've had a vasectomy. 2)You can't get an erection with a truckload of viagra. 3)You haven't slept in the same bed or had sex with your wife for 2 years. You divorce your wife. Your wife requests child support from you because you make a million dollars a year and the real father is a deadbeat. Guess what? The law presumes you are the father because you were married to her when she became pregnant. You can stand in court all day and state till you're blue in the face that you're not the childs father and she hasn't proved that I am (ie; you never got the letter). Guess what? You'll be paying child support because the law must presume you to be the childs father. The law must presume, however you are allowed the opportunity to rebut that presumption with credible proof. Such as a DNA test. A rebuttable presumption is a larger matter than just "he said, she said," as is being suggested. It is quite simply a matter of "guilty until proven innocent," and the burden of proof is yours.......not your wife's. If a CA can show standard mailing practices are in place, the law presumes you received any letter they send shortly after it was mailed. You would need credible proof to rebut that presumption. Your 30 day clock begins upon that presumed receipt of the letter they show was mailed.....not whenever you choose to decide to request it because you state "I never got the letter, prove I did."