diff --git a/event_handler.go b/event_handler.go
index 1a4d67c..27bc3fe 100644
--- a/event_handler.go
+++ b/event_handler.go
@@ -36,7 +36,46 @@ func eventHandler(ctx *IrcContext, rtm *slack.RTM) {
 				}
 			} else if strings.HasPrefix(ev.Msg.Channel, "D") {
 				// Direct message to me
-				channame = ctx.Nick
+				users, err := usersInConversation(ctx, ev.Msg.Channel)
+				if err != nil {
+					// ERR_UNKNOWNERROR
+					SendIrcNumeric(ctx, 400, ctx.Nick, fmt.Sprintf("Cannot get conversation info for %s", ev.Msg.Channel))
+					return
+				}
+				// we expect only two members in a direct message. Raise an
+				// error if not.
+				if len(users) != 2 {
+					// ERR_UNKNOWNERROR
+					SendIrcNumeric(ctx, 400, ctx.Nick, fmt.Sprintf("Exactly two users expected in direct message, got %d (conversation ID: %s)", len(users), ev.Msg.Channel))
+					return
+
+				}
+				// of the two users, one is me. Otherwise fail
+				if ctx.UserID() == "" {
+					// ERR_UNKNOWNERROR
+					SendIrcNumeric(ctx, 400, ctx.UserID(), "Cannot get my own user ID")
+					return
+				}
+				if users[0] != ctx.UserID() && users[1] != ctx.UserID() {
+					// ERR_UNKNOWNERROR
+					SendIrcNumeric(ctx, 400, ctx.UserID(), fmt.Sprintf("Got a direct message where I am not part of the members list (members: %s)", strings.Join(users, ", ")))
+					return
+				}
+				var recipientID string
+				if users[0] == ctx.UserID() {
+					// then it's the other user
+					recipientID = users[1]
+				} else {
+					recipientID = users[0]
+				}
+				// now resolve the ID to the user's nickname
+				nickname := ctx.GetUserInfo(recipientID)
+				if nickname == nil {
+					// ERR_UNKNOWNERROR
+					SendIrcNumeric(ctx, 400, ctx.UserID(), fmt.Sprintf("Unknown destination user ID %s for direct message %s", recipientID, ev.Msg.Channel))
+					return
+				}
+				channame = nickname.Name
 			} else {
 				log.Printf("Unknown recipient ID: %s", ev.Msg.Channel)
 				return
diff --git a/irc_context.go b/irc_context.go
index 192f0d2..3666698 100644
--- a/irc_context.go
+++ b/irc_context.go
@@ -70,6 +70,15 @@ func (ic *IrcContext) GetUserInfoByName(username string) *slack.User {
 	return nil
 }
 
+// UserID returns the user's Slack ID
+func (ic IrcContext) UserID() string {
+	user := ic.GetUserInfoByName(ic.Nick)
+	if user == nil {
+		return ""
+	}
+	return user.ID
+}
+
 // Mask returns the IRC mask for the current user
 func (ic IrcContext) Mask() string {
 	var username string
diff --git a/irc_server.go b/irc_server.go
index 9d38eef..aa3af51 100644
--- a/irc_server.go
+++ b/irc_server.go
@@ -106,20 +106,16 @@ func IrcSendChanInfoAfterJoin(ctx *IrcContext, name, topic string, members []str
 	ctx.ChanMutex.Unlock()
 }
 
-// join will join the channel with the given ID, name and topic, and send back a
-// response to the IRC client
-func join(ctx *IrcContext, id, name, topic string) {
+func usersInConversation(ctx *IrcContext, conversation string) ([]string, error) {
 	var (
-		info       string
 		members, m []string
 		nextCursor string
 		err        error
 	)
 	for {
-		m, nextCursor, err = ctx.SlackClient.GetUsersInConversation(&slack.GetUsersInConversationParameters{ChannelID: id, Cursor: nextCursor})
+		m, nextCursor, err = ctx.SlackClient.GetUsersInConversation(&slack.GetUsersInConversationParameters{ChannelID: conversation, Cursor: nextCursor})
 		if err != nil {
-			log.Printf("Cannot get member list for channel %s: %v", name, err)
-			break
+			return nil, fmt.Errorf("Cannot get member list for conversation %s: %v", conversation, err)
 		}
 		members = append(members, m...)
 		log.Printf(" nextCursor=%v", nextCursor)
@@ -127,12 +123,23 @@ func join(ctx *IrcContext, id, name, topic string) {
 			break
 		}
 	}
-	info = "(joined) "
+	return members, nil
+}
+
+// join will join the channel with the given ID, name and topic, and send back a
+// response to the IRC client
+func join(ctx *IrcContext, id, name, topic string) error {
+	members, err := usersInConversation(ctx, id)
+	if err != nil {
+		return err
+	}
+	info := "(joined) "
 	info += fmt.Sprintf(" topic=%s members=%d", topic, len(members))
 	log.Printf(info)
 	// the channels are already joined, notify the IRC client of their
 	// existence
 	go IrcSendChanInfoAfterJoin(ctx, name, topic, members, false)
+	return nil
 }
 
 // joinChannels gets all the available Slack channels and sends an IRC JOIN message
@@ -156,7 +163,9 @@ func joinChannels(ctx *IrcContext) error {
 	}
 	for _, ch := range channels {
 		if ch.IsMember {
-			join(ctx, ch.ID, ch.Name, ch.Topic.Value)
+			if err := join(ctx, ch.ID, ch.Name, ch.Topic.Value); err != nil {
+				return err
+			}
 		}
 	}
 	return nil
@@ -184,119 +193,6 @@ func IrcAfterLoggingIn(ctx *IrcContext, rtm *slack.RTM) error {
 	}
 
 	go eventHandler(ctx, rtm)
-	/*
-		go func(rtm *slack.RTM) {
-			log.Print("Started Slack event listener")
-			for msg := range rtm.IncomingEvents {
-				switch ev := msg.Data.(type) {
-				case *slack.MessageEvent:
-					// get user
-					var name string
-					user := ctx.GetUserInfo(ev.Msg.User)
-					if user == nil {
-						log.Printf("Error getting user info for %v", ev.Msg.User)
-						name = ev.Msg.User
-					} else {
-						name = user.Name
-					}
-					// get channel or other recipient (e.g. recipient of a direct message)
-					var channame string
-					if strings.HasPrefix(ev.Msg.Channel, "C") {
-						// Channel message
-						// TODO cache channel info
-						channel, err := ctx.SlackClient.GetChannelInfo(ev.Msg.Channel)
-						if err != nil {
-							log.Printf("Error getting channel info for %v: %v", ev.Msg.Channel, err)
-							channame = "unknown"
-						} else {
-							channame = "#" + channel.Name
-						}
-					} else if strings.HasPrefix(ev.Msg.Channel, "D") {
-						// Direct message to me
-						channame = ctx.Nick
-					} else {
-						log.Printf("Unknown recipient ID: %s", ev.Msg.Channel)
-						return
-					}
-
-					log.Printf("SLACK msg from %v (%v) on %v: %v",
-						ev.Msg.User,
-						name,
-						ev.Msg.Channel,
-						ev.Msg.Text,
-					)
-					if ev.Msg.User == "" && ev.Msg.Text == "" {
-						log.Printf("WARNING: empty user and message: %+v", ev.Msg)
-						continue
-					}
-					// replace UIDs with user names
-					text := ev.Msg.Text
-					// replace UIDs with nicknames
-					text = rxSlackUser.ReplaceAllStringFunc(text, func(subs string) string {
-						uid := subs[2 : len(subs)-1]
-						user := ctx.GetUserInfo(uid)
-						if user == nil {
-							return subs
-						}
-						return fmt.Sprintf("@%s", user.Name)
-					})
-					// replace some HTML entities
-					text = ExpandText(text)
-
-					// FIXME if two instances are connected to the Slack API at the
-					// same time, this will hide the other instance's message
-					// believing it was sent from here. But since it's not, both
-					// local echo and remote message won't be shown
-					botID := msg.Data.(*slack.MessageEvent).BotID
-					if name == ctx.Nick && botID != user.Profile.BotID {
-						// don't print my own messages
-						continue
-					}
-					// handle multi-line messages
-					for _, line := range strings.Split(text, "\n") {
-						privmsg := fmt.Sprintf(":%v!%v@%v PRIVMSG %v :%v\r\n",
-							name, ev.Msg.User, ctx.ServerName,
-							channame, line,
-						)
-						log.Print(privmsg)
-						ctx.Conn.Write([]byte(privmsg))
-					}
-					msgEv := msg.Data.(*slack.MessageEvent)
-					// Check if the topic has changed
-					if msgEv.Topic != ctx.Channels[msgEv.Channel].Topic {
-						// Send out new topic
-						channel, err := ctx.SlackClient.GetChannelInfo(msgEv.Channel)
-						if err != nil {
-							log.Printf("Cannot get channel name for %v", msgEv.Channel)
-						} else {
-							newTopic := fmt.Sprintf(":%v TOPIC #%v :%v\r\n", ctx.Mask(), channel.Name, msgEv.Topic)
-							log.Printf("Got new topic: %v", newTopic)
-							ctx.Conn.Write([]byte(newTopic))
-						}
-					}
-					// check if new people joined the channel
-					added, removed := ctx.Channels[msgEv.Channel].MembersDiff(msgEv.Members)
-					if len(added) > 0 || len(removed) > 0 {
-						log.Printf("[*] People who joined: %v", added)
-						log.Printf("[*] People who left: %v", removed)
-					}
-				case *slack.ConnectedEvent:
-					log.Print("Connected to Slack")
-					ctx.SlackConnected = true
-				case *slack.DisconnectedEvent:
-					log.Printf("Disconnected from Slack (intentional: %v)", msg.Data.(*slack.DisconnectedEvent).Intentional)
-					ctx.SlackConnected = false
-					ctx.Conn.Close()
-				case *slack.MemberJoinedChannelEvent, *slack.MemberLeftChannelEvent:
-					// refresh the users list
-					// FIXME also send a JOIN / PART message to the IRC client
-					ctx.GetUsers(true)
-				default:
-					log.Printf("SLACK event: %v: %v", msg.Type, msg.Data)
-				}
-			}
-		}(rtm)
-	*/
 	return nil
 }