I would suggest is that in an alliance ogame, as in other games like Wildguns KingsAge and where there is a forum within the alliance itself.
In wildguns, for example, has opição to mark the alliances that have agreements with you and who are enemies to be marked on the map (in our case, Galaxy).
In this internal forum, could post offers of features, post their attacks that do not qualify to be posted on the official forum, or you do not want to expose its fleet in there for all to see just your friends.
It would be a better way of communication between members of the alliance, because only the MCs Across gets very boring.