client remote add===>IV,sig{sn(from server)},sn(from server),cipher text{mail list,group list} ==>server.

server response remote add ===> IV,cipher text{sn(old),sn(new from server)},error code===>client.

client remote del===>sig{sn},IV,cipher text{mail list,group list} ==>server.

server response remote del ===> IV,cipher text{sn(old),sn(new from server)},error code===client.

server response hello ===IV,sig{sn(from client)},sn(from server) ==>client.

client pull mail list or group list ===>sig{sn(from server)},IV,cipher text{command(pull mail list or pull all or pull group)} ==server.

server response pull ===>IV,cipher text{mail list,group list,sn(old),sn(new from server)}.

client hello.

ErrId: 0: success 1: Receipt Address not found 2: Receipt Address is forbidden 3: Data is forbidden 4: bmail command Not Found 5: Mail to large 6: Mail refused by server 7: Connect to Server failed */server -> client.

server -> client.

client -> server.