What is the plural of mister?

Answer by  palaeologus (564)

Formal correspondence addressed to one man should use "Mr." as a title of respect, which is changed to "Messrs." (from the French "Messieurs") when more than one man is addressed.

Answer by  sofaltis (13)

An older plural form of Mister would be Messrs. It might be better in a modern format to put Dear Sirs, etc.