Our home mortgage

We recently received a "deal" in the mail from our mortgage company. They claim that by signing up for their program we could save $13,000 in interest and pay off our loan 4 years earlier. I read all the fine print and did the math and discovered instead of monthly payments there would be biweekly withdrawals from our checking account tied to paydays plus $5 more in payments each month. There is a one time enrollment fee of $295 and a monthly participation fee of $5.42. I quote from the paperwork, "That's a small amount compared to your projected interest savings of over $13,000."
When I bought my first house my realtor gave me the advice to make one extra payment a year and it would work out to paying off the 30 year mortgage about 10 years earlier. From the beginning of this mortgage we have been rounding up and putting extra in each payment. At the end of the year we will round up to make it a full extra payment if we haven't completed that yet.
I think I'll stick with my system and put all the money that I would be putting into fees into paying off the mortgage instead of paying fees. The crazy part is that I would be paying all these fees to them so they would be guaranteed an on time payment each month plus they would save the cost of postage!