While convenient, our modern, LOL-based repartee has left us tragically inept at even the simplest formal missive. Sux. Outsource your scribbling to NY's Bureau of Communication.
Like a Mad Libs for pro-forma communiques, BoC's fill-in-the-blank web-stationery facilitates the dispatches etiquette demands, but your laziness/illiteracy prevents. There are six forms total, from Airing of Grievance, to Observance of Holiday, to Formal Apology, each with blanks for nouns/verbs and checkboxes allowing you to express sentiment ("Has it been another year already?") or qualify your behavior ("You were never supposed to know"). The completed forms can then be easily emailed or, if you're feeling particularly emotive, printed -- because there's no better indication of heartfeltness than walking to the Epson 9000.