Q: Do we still use Messrs. when addressing two men with the same last name in a letter salutation?
A: When correspondence is being addressed to a group of men, or they are being introduced collectively, one may use “Messrs. Gordon, Kauffman, and Legeloh,” or the definite article “the” may be used: “The Messrs…”
“The Messrs. Bomann” may be used for two brothers, but not for relatives of different generations, such as a father and son or a grandfather and grandson. When correspondence is addressed to two of three or more brothers in one family, their first names are used and you would write: “The Messrs. Reid and Thomas Coleman.”