public Either <string, bool> CanAccept <T>() => Inbox.CanAcceptMessageType <T>();
public bool CanAccept <T>() => Inbox.CanAcceptMessageType <T>();
public Either <string, bool> CanAccept <T>() => Inbox.CanAcceptMessageType <T>();
public bool CanAccept <T>() => Inbox.CanAcceptMessageType <T>();