if let Some(from) = presence.from {
                        if let Some(ref mut mailbox) = self
                            .state
                            .data
                            .outgoing_mailbox
                            .remove(&from.clone().into())
                        {
                            if !mailbox.is_empty() {
                                warn!(
                                    "Removed {} undeliverable messages for {}",
                                    mailbox.len(),
                                    from
                                );
                            }
                        }
                    }