how to address a letter to three (3) men, is it Dear Misters Joe Smith, Paul Jones & Tim Crooks?
or Dear Mr. Smith, Mr. Jones & Mr. Crooks?
Or you could put: Dear Messrs Smith, Jones & Crooks.
It would depend upon the relationship between the three men. If they are in business together or if they are working together on a joint project and they are all available at the same address then either would do. There must be a connection between the three.