I'm not sure as to the answer to your question, but as a commish I demand an email address from all. The commish should be able to get in touch with the owners outside of using the league messaging system. IMO I do group emails through my email as I can't stand the messaging system on the NFL site, I also have a league facebook page, there is were I post most info and this is how we discuss it. Just some things to consider to avoid this in the future.
10 team 4 keeper PPR league: (Starters in bold)
RB: A.Peterson. Sproles, Murray (flex), DeAngelo Williams
WR: Julio Jones, Cruz,Garcon, Jeffrey, Douglas, ROyal