The List
There are 181 5 letter words with M as the last letter. The highest scoring is ZUZIM at 25 points in Scrabble. 15 carry three or more vowels, which makes them useful for dumping a vowel-clogged rack.
ABEAMABOHMABRAMABRIMABYSMADEEMADSUMAGISMALARMALBUMALGUMAPISMASSAMASWIMAURUMAXIOMBEDIMBEGEMBEGUMBESOMBISOMBLOOMBOSOMBREAMBREEMBROOMBUXOMCAROMCECUMCELOMCHARMCHASMCHIRMCHOOMCLAIMCLOAMCORAMCREAMCUSUMDATUMDEGUMDEISMDENIMDIRAMDREAMDUNAMDURUMDWALMDWAUMENARMENORMENZYMEXEEMFANUMFILUMFLAMMFLEAMFORAMFORUMFRAIMGARUMGENOMGLAUMGLEAMGLOAMGLOOMGOLEMGOYIMGROOMHAKAMHAKIMHARAMHAREMHARIMHAULMHILUMHOKUMIDIOMIHRAMILEUMILIUMIMAUMINARMINERMJORAMJORUMJUGUMKALAMKELIMKHOUMKILIMKOKUMLARUMLEDUMLINUMLOCUMMADAMMALAMMAXIMMIASMMINIMMODEMNIZAMNOTUMNOVUMOAKUMOCCAMODEUMODISMODIUMOGHAMOLEUMONIUMOPIUMPANIMPASHMPHARMPILUMPLASMPRAAMPRISMPROEMPSALMQUALMREALMREARMREHEMRETEMRHEUMSAGUMSATEMSCLIMSCRAMSCRIMSCRUMSEBUMSEDUMSEISMSERUMSHALMSHAWMSHTUMSKELMSKLIMSLOOMSLORMSMALMSMARMSODOMSOLUMSPASMSPERMSPOOMSTEAMSTEEMSTORMSTRIMSTRUMSTULMSTUMMSWARMTHAIMTHARMTHERMTHRUMTOTEMTUISMUNARMUNDAMUNGUMUNJAMVELUMVENOMVROOMWHELMXYLEMYEALMYOMIMZIRAMZOISMZUZIM