13 possible answers to
Answers with 3 characters: ATT ELL SIR Answers with 4 characters: DEAR SIRS Answers with 5 characters: ALPHA MADAM STEAM Answers with 6 characters: MESSRS TOWHOM Answers with 7 characters: DEARSIR Answers with 9 characters: ADDRESSEE Answers with 10 characters: PAPERKNIFE