Catalyzes the transmethylation of nonepinephrine (noradrenaline) to form epinephrine (adrenaline), using S-adenosyl-L-methionine as the methyl donor (PubMed:20496117). Other substrates include phenylethanolamine and octopamine (PubMed:8812853, PubMed:16363801, PubMed:16277617). Also methylates normetanephrine (By similarity). phenylethanolamine + S-adenosyl-L-methionine = H(+) + N-methylphenylethanolamine + S-adenosyl-L-homocysteine (R)-noradrenaline + S-adenosyl-L-methionine = (R)-adrenaline + H(+) + S-adenosyl-L-homocysteine (R)-normetanephrine + S-adenosyl-L-methionine = H(+) + N-methyl-(R)-normetanephrine + S-adenosyl-L-homocysteine (R)-octopamine + S-adenosyl-L-methionine = (R)-synephrine + H(+) + S-adenosyl-L-homocysteine Inhibited by methyl methanethiosulfonate, phenylglyoxal, tetranitromethane and diethyl pyrocarbonate (PubMed:8812853). Inhibited by 4-oxo-1,4-dihydro-quinoline-3,7-dicarboxylic acid, 4-(benzo[d][1,3]dioxol-5-ylamino)-4-oxobutanoic acid and 1,4-diaminonaphthalene-2,6-disulfonic acid (PubMed:20496117). Catecholamine biosynthesis; (R)-adrenaline biosynthesis; (R)-adrenaline from (R)-noradrenaline: step 1/1. Belongs to the class I-like SAM-binding methyltransferase superfamily. NNMT/PNMT/TEMT family.