[ by Melanie Gretchen ] Today's Lesson: There's More to Compliance Than the SEC and FINRA. TD Ameritrade agreed to pay $1.5 million to settle charges that it violated rules and received discounts, to which it wasn't entitled.  FINRA?  The SEC?  No, U.S. Postal Service. According to Nebraska-based U.S. Attorney Deborah Gilg, a unit of TD Ameritrade sent out mailings over a 3-year period - October 2006 to September 2009 - that were not eligible for the discounted first-class postage rate the firm claimed.  It seems, prosecutors said, the broker-dealer had failed to update its addresses with a postal database of change-of-address information prior to sending them out.  Such rules are designed to reduce the amount of mail that has to be forwarded or returned. For more details, go to [Associated Press, 2/7/12].