diff --git a/src/Invite.js b/src/Invite.js
index 678a838bf1..6422812734 100644
--- a/src/Invite.js
+++ b/src/Invite.js
@@ -59,6 +59,12 @@ export function inviteMultipleToRoom(roomId, addrs) {
     return this.inviter.invite(addrs);
 }
 
+/**
+ * Checks is the supplied address is valid
+ *
+ * @param {addr} The mx userId or email address to check
+ * @returns true, false, or null for unsure
+ */
 export function isValidAddress(addr) {
     // Check if the addr is a valid type
     var addrType = this.getAddressType(addr);
@@ -67,7 +73,7 @@ export function isValidAddress(addr) {
         if (user) {
             return true;
         } else {
-            return false;
+            return null;
         }
     } else if (addrType === "email") {
         return true;
diff --git a/src/components/views/dialogs/ChatInviteDialog.js b/src/components/views/dialogs/ChatInviteDialog.js
index a2471092d0..7f04986b6b 100644
--- a/src/components/views/dialogs/ChatInviteDialog.js
+++ b/src/components/views/dialogs/ChatInviteDialog.js
@@ -120,7 +120,8 @@ module.exports = React.createClass({
         } else if (e.keyCode === 32 || e.keyCode === 188) { // space or comma
             e.stopPropagation();
             e.preventDefault();
-            if (Invite.isValidAddress(this.refs.textinput.value)) {
+            var check = Invite.isValidAddress(this.refs.textinput.value);
+            if (check === true || check === null) {
                 var inviteList = this.state.inviteList.slice();
                 inviteList.push(this.refs.textinput.value);
                 this.setState({
diff --git a/src/components/views/elements/AddressTile.js b/src/components/views/elements/AddressTile.js
index a6b86c12b2..f81bb3dff0 100644
--- a/src/components/views/elements/AddressTile.js
+++ b/src/components/views/elements/AddressTile.js
@@ -59,8 +59,8 @@ module.exports = React.createClass({
                 name = user.displayName || userId;
                 imgUrl = Avatar.avatarUrlForUser(user, 25, 25, "crop");
             } else {
-                name="Unknown";
-                imgUrl = "img/avatar-error.svg";
+                name=this.props.address;
+                imgUrl = "img/icon-mx-user.svg";
             }
         } else if (addrType === "email") {
             email = this.props.address;
@@ -82,7 +82,7 @@ module.exports = React.createClass({
 
         var info;
         var error = false;
-        if (userId) {
+        if (addrType === "mx" && userId) {
             var nameClasses = classNames({
                 "mx_AddressTile_name": true,
                 "mx_AddressTile_justified": this.props.justified,
@@ -99,6 +99,15 @@ module.exports = React.createClass({
                     <div className={idClasses}>{ userId }</div>
                 </div>
             );
+        } else if (addrType === "mx") {
+            var unknownMxClasses = classNames({
+                "mx_AddressTile_unknownMx": true,
+                "mx_AddressTile_justified": this.props.justified,
+            });
+
+            info = (
+                <div className={unknownMxClasses}>{ this.props.address }</div>
+            );
         } else if (email)  {
             var emailClasses = classNames({
                 "mx_AddressTile_email": true,