diff --git a/lib/account.js b/lib/account.js
index f725642..495b9fa 100644
--- a/lib/account.js
+++ b/lib/account.js
@@ -1,270 +1,273 @@
 'use strict';
 
 import debug from 'debug';
 import md5 from 'blueimp-md5';
 import transform from 'sdp-transform';
 import utils from './utils';
 
 import { EventEmitter } from 'events';
 import { Call } from './call';
 import { ConferenceCall } from './conference';
 import { Message } from './message';
 
 const DEBUG = debug('sylkrtc:Account');
 
 
 class Account extends EventEmitter {
     constructor(options, connection) {
         if (options.account.indexOf('@') === -1) {
             throw new Error('Invalid account id specified');
         }
         super();
         const id = options.account;
         const [username, domain] = id.split('@');
         this._id = id;
         this._displayName = options.displayName;
         if (options.hasOwnProperty('ha1') && !options.ha1) {
             this._password = options.password;
         } else {
             this._password = md5(username + ':' + (options.realm || domain)+ ':' + options.password);
         }
         this._connection = connection;
         this._registrationState = null;
         this._calls = new Map();
         this._confCalls = new Map();
         this._messages = new Map();
     }
 
     get id() {
         return this._id;
     }
 
     get password() {
         return this._password;
     }
 
     get displayName() {
         return this._displayName;
     }
 
     get registrationState() {
         return this._registrationState;
     }
 
     get messages() {
         return Array.from(this._messages.values());
     }
 
     register() {
         const req = {
             sylkrtc: 'account-register',
             account: this._id
         };
         this._sendRequest(req, (error) => {
             if (error) {
                 DEBUG('Register error: %s', error);
                 const oldState = this._registrationState;
                 const newState = 'failed';
                 const data = {reason: error.toString()};
                 this._registrationState = newState;
                 this.emit('registrationStateChanged', oldState, newState, data);
             }
         });
     }
 
     unregister() {
         const req = {
             sylkrtc: 'account-unregister',
             account: this._id,
         };
         this._sendRequest(req, (error) => {
             if (error) {
                 DEBUG('Unregister error: %s', error);
             }
             const oldState = this._registrationState;
             const newState = null;
             this._registrationState = newState;
             this.emit('registrationStateChanged', oldState, newState, {});
         });
     }
 
     call(uri, options={}) {
         const callObj = new Call(this);
         callObj._initOutgoing(uri, options);
         this._calls.set(callObj.id, callObj);
         this.emit('outgoingCall', callObj);
         return callObj;
     }
 
     joinConference(uri, options={}) {
         const confCall = new ConferenceCall(this);
         confCall._initialize(uri, options);
         this._confCalls.set(confCall.id, confCall);
         this.emit('conferenceCall', confCall);
         return confCall;
     }
 
     setDeviceToken(token, platform, device, silent, app) {
         DEBUG('Setting device token: %s', token);
         const req = {
             sylkrtc: 'account-devicetoken',
             account: this._id,
             token,
             platform,
             device,
             silent,
             app
         };
         this._sendRequest(req, (error) => {
             if (error) {
                 DEBUG('Error setting device token: %s', error);
             }
         });
     }
 
     sendMessage(uri, message, contentType='text/plain') {
         const outgoingMessage = new Message({
             account: uri,
             content: message,
             contentType,
             timestamp: new Date().toISOString(),
             type: 'normal'
         }, new utils.Identity(this._id, this._displayName), 'pending');
         const req = {
             sylkrtc: 'account-message',
             account: this._id,
             uri: uri,
             message_id: outgoingMessage.id,
             content: outgoingMessage.content,
             content_type: outgoingMessage.contentType,
             timestamp: outgoingMessage.timestamp
         };
         this._messages.set(outgoingMessage.id, outgoingMessage);
         this.emit('sendingMessage', outgoingMessage);
         DEBUG('Sending message: %o', outgoingMessage);
         this._sendRequest(req, (error) => {
             if (error) {
                 DEBUG('Error sending message: %s', error);
                 outgoingMessage._setState('failed');
             }
         });
         return outgoingMessage;
     }
 
     sendDispositionNotification(uri, id, timestamp, state, cb=null) {
         const req = {
             sylkrtc: 'account-disposition-notification',
             account: this._id,
             uri: uri,
             message_id: id,
             state,
             timestamp
         };
         DEBUG('Sending disposition notification: %o', req);
         this._sendRequest(req, (error) => {
             if (error) {
                 DEBUG('Error sending disposition notification: %s', error);
             } else {
                 const incomingMessage = this._messages.get(id);
                 if (incomingMessage) {
                     incomingMessage._setDispositionState(state);
                 }
             }
             this.emit('sendingDispositionNotification', id, state, error);
             if (cb) {
                 cb(error);
             }
         });
     }
 
     removeChat(uri) {
         for (let [id, message] of this._messages.entries()) {
             if (message.state === 'received' && message.sender.uri === uri) {
                 this._messages.delete(id);
             } else if (message.receiver === uri) {
                 this._messages.delete(id);
             }
         }
     }
 
     // Private API
 
     _handleEvent(message) {
         DEBUG('Received account event: %s', message.event);
         const data = {};
         switch (message.event) {
             case 'registration-state':
                 const oldState = this._registrationState;
                 const newState = message.state;
                 this._registrationState = newState;
                 if (newState === 'failed') {
                     data.reason = message.reason;
                 }
                 this.emit('registrationStateChanged', oldState, newState, data);
                 break;
             case 'incoming-session':
                 let call = new Call(this);
                 call._initIncoming(message.session, message.originator, message.sdp, message.call_id);
                 this._calls.set(call.id, call);
                 // see what media types are offered
                 const mediaTypes = { audio: false, video: false };
                 const parsedSdp = transform.parse(message.sdp);
                 for (let media of parsedSdp.media) {
                     if (media.type === 'audio' && media.port !== 0 && media.direction === 'sendrecv') {
                         mediaTypes.audio = true;
                     } else if (media.type === 'video' && media.port !== 0 && media.direction === 'sendrecv') {
                         mediaTypes.video = true;
                     }
                 }
                 DEBUG('Incoming call from %s with media types: %o', message.originator.uri, mediaTypes);
                 this.emit('incomingCall', call, mediaTypes);
                 break;
             case 'missed-session':
                 data.originator = new utils.Identity(message.originator.uri, message.originator.display_name);
                 this.emit('missedCall', data);
                 break;
             case 'conference-invite':
                 data.originator = new utils.Identity(message.originator.uri, message.originator.display_name);
                 data.room = message.room;
                 data.id = message.session_id;
                 this.emit('conferenceInvite', data);
                 break;
             case 'message':
                 DEBUG('Incoming message from %s: %o', message.sender.uri, message);
                 const incomingMessage = this._messages.get(message.message_id);
                 if (!incomingMessage) {
                     const mappedMessage = new Message(
                         message,
                         new utils.Identity(message.sender.uri, message.sender.display_name),
                         'received'
                     );
                     this._messages.set(mappedMessage.id, mappedMessage);
                     if (message.disposition_notification && message.disposition_notification.indexOf('positive-delivery') !== -1) {
                         this.sendDispositionNotification(message.sender.uri, message.message_id, message.timestamp, 'delivered');
                     }
                     this.emit('message', mappedMessage);
                 }
                 break;
             case 'disposition-notification':
                 const outgoingMessage = this._messages.get(message.message_id);
                 if (outgoingMessage) {
+                    if (outgoingMessage.state === 'displayed') {
+                        break;
+                    }
                     outgoingMessage._setState(message.state);
                 }
                 this.emit('messageStateChanged', {
                     messageId: message.message_id,
                     state: message.state
                 });
                 break;
             default:
                 break;
         }
     }
 
     _sendRequest(req, cb) {
         this._connection._sendRequest(req, cb);
     }
 
 }
 
 
 export { Account };