I'm creating a custom MTM, and I wanted to add my MTM to the "New Message" CBA menu. I followed the instuctions here and got my MTM on the menu.

When I click on the menu the following happens:
1) My UI MTM's QueryCapability function is called with 268458513(0x10005a11). I have no idea what this capability means, but I noticed that if I have to return KErrNone and put something other that 0 in aResponse, otherwise that's where the story ends.
2) Then InvokeSyncFunctionL (still in my UI MTM) is called with 2109446(0x203006) as the operation ID. Again, I have no idea what this is but I can simply call CreateL() from here and the editor opens.

But when I exit the editor I always get a note telling me "Unable to create message. Message settings must be first defined in Messaging". This is even though the message has been created. Does anyone know the meaning of this note, or the capability and function IDs I'm getting?

And in the Contacts app's "Create message" menu I can see my MTM, but when I click the option nothing happens.