It’s been 9 years since I blogged on SEND MORE MONEY. I got back into this because I found out that the author of SEND MORE MONEY is Henry Dudeney and the puzzle apparently appeared in Strand Magazine vol. 68 (July 1924), pp. 97 and 214. Dudeney calls this Verbal Arithmetic. The Wikipedia entry on Dudeney casts doubts that he was the inventor and cites this 1864 example. However, the cited example does not have the feature that the letters make up sensible words. In fact, the words often make up sensible sentences.
The SEND+SOME+MORE=MONEY is my own invention but I don’t claim it to be original since it is not much of a stretch from Dudeney’s problem. Unfortunately, teaching duties beckon and I cannot spend time cracking it. Mathematica comes to the rescue and I already found four distinct solutions by simply assuming M=2.