3 letters:
mel

4 letters:
mehl, meld, meli, mell, melo, melt

5 letters:
ehler, eller, maler, medar, meger, mel's, mella, melle, melli, mello, melly, meloy, menor, miler, moler, myler

6 letters:
behler, bellar, beller, cellar, dehler, deller, feller, geller, heller, kehler, kellar, keller, maeder, mahler, mailer, maller, mauler, mealer, mealor, medlar, medler, meeler, mehner, mehrer, melder, melley, mellie, mellow, melnor, melzer, memmer, messer, metter, mettur, millar, miller, mohler, moller, muller, neller, peller, reller, seller, shelor, teller, wehler, weller, zeller, mehler, melear, mellor

7 letters:
kaehler, kneller, measure, mechler, meckler, melcher, melchor, mescher, messler, mettler, moeller, sheller