Catalyzes the transmethylation of nonepinephrine (noradrenaline) to form epinephrine (adrenaline), using S-adenosyl-L-methionine as the methyl donor (PubMed:13863458). Other substrates include phenylethanolamine, octopamine and normetanephrine (PubMed:13863458). 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 p-chloromercuribenaoate. Optimum pH is 8-9. Catecholamine biosynthesis; (R)-adrenaline biosynthesis; (R)-adrenaline from (R)-noradrenaline: step 1/1. Expressed in the adrenal medulla. Belongs to the class I-like SAM-binding methyltransferase superfamily. NNMT/PNMT/TEMT family.