diff --git a/app/src/main/java/com/nextcloud/talk/adapters/ParticipantsAdapter.java b/app/src/main/java/com/nextcloud/talk/adapters/ParticipantsAdapter.java
index 2275a7f7d..c6c49773d 100644
--- a/app/src/main/java/com/nextcloud/talk/adapters/ParticipantsAdapter.java
+++ b/app/src/main/java/com/nextcloud/talk/adapters/ParticipantsAdapter.java
@@ -148,7 +148,7 @@ public class ParticipantsAdapter extends BaseAdapter {
                 participantDisplayItem.getActorType() == Participant.ActorType.EMAILS) {
                 ImageViewExtensionsKt.loadFirstLetterAvatar(
                     imageView,
-                    String.valueOf(participantDisplayItem.getNick().charAt(0))
+                    String.valueOf(participantDisplayItem.getNick())
                 );
             } else {
                 ImageViewExtensionsKt.loadAvatarWithUrl(imageView,null, participantDisplayItem.getUrlForAvatar());
diff --git a/app/src/main/java/com/nextcloud/talk/adapters/items/ConversationItem.kt b/app/src/main/java/com/nextcloud/talk/adapters/items/ConversationItem.kt
index e047be397..d08ff37a4 100644
--- a/app/src/main/java/com/nextcloud/talk/adapters/items/ConversationItem.kt
+++ b/app/src/main/java/com/nextcloud/talk/adapters/items/ConversationItem.kt
@@ -20,6 +20,7 @@ import androidx.core.content.ContextCompat
 import androidx.core.content.res.ResourcesCompat
 import com.nextcloud.talk.R
 import com.nextcloud.talk.adapters.items.ConversationItem.ConversationItemViewHolder
+import com.nextcloud.talk.adapters.messages.MessagePayload
 import com.nextcloud.talk.application.NextcloudTalkApplication.Companion.sharedApplication
 import com.nextcloud.talk.chat.data.model.ChatMessage.MessageType
 import com.nextcloud.talk.data.database.mappers.asModel
@@ -249,14 +250,15 @@ class ConversationItem(
         } else if (model.type == ConversationEnums.ConversationType.ROOM_TYPE_ONE_TO_ONE_CALL) {
             lastMessageDisplayText
         } else {
-            val authorDisplayName =
-                if (!TextUtils.isEmpty(chatMessage?.actorDisplayName)) {
-                    chatMessage?.actorDisplayName
-                } else if ("guests" == chatMessage?.actorType) {
-                    appContext.getString(R.string.nc_guest)
-                } else {
-                    ""
-                }
+            val actorName = chatMessage?.actorDisplayName
+            val authorDisplayName = if (!actorName.isNullOrBlank()) {
+                actorName
+            } else if ("guests" == chatMessage?.actorType || "emails" == chatMessage?.actorType) {
+                appContext.getString(R.string.nc_guest)
+            } else {
+                ""
+            }
+
             String.format(
                 appContext.getString(R.string.nc_formatted_message),
                 authorDisplayName,
diff --git a/app/src/main/java/com/nextcloud/talk/adapters/items/MentionAutocompleteItem.kt b/app/src/main/java/com/nextcloud/talk/adapters/items/MentionAutocompleteItem.kt
index 3e3ba686f..721666982 100644
--- a/app/src/main/java/com/nextcloud/talk/adapters/items/MentionAutocompleteItem.kt
+++ b/app/src/main/java/com/nextcloud/talk/adapters/items/MentionAutocompleteItem.kt
@@ -16,6 +16,7 @@ import androidx.core.content.res.ResourcesCompat
 import com.nextcloud.talk.R
 import com.nextcloud.talk.adapters.items.ParticipantItem.ParticipantItemViewHolder
 import com.nextcloud.talk.data.user.model.User
+import com.nextcloud.talk.extensions.loadDefaultAvatar
 import com.nextcloud.talk.extensions.loadFederatedUserAvatar
 import com.nextcloud.talk.extensions.loadGuestAvatar
 import com.nextcloud.talk.extensions.loadUserAvatar
@@ -56,7 +57,15 @@ class MentionAutocompleteItem(
     init {
         mentionId = mention.mentionId
         objectId = mention.id
-        displayName = mention.label
+
+        displayName = if (!mention.label.isNullOrBlank()) {
+            mention.label
+        } else if ("guests" == mention.source || "emails" == mention.source) {
+            context.resources.getString(R.string.nc_guest)
+        } else {
+            ""
+        }
+
         source = mention.source
         status = mention.status
         statusIcon = mention.statusIcon
@@ -149,7 +158,11 @@ class MentionAutocompleteItem(
 
             SOURCE_GUESTS, SOURCE_EMAILS -> {
                 avatarId = displayName
-                holder.binding.avatarView.loadGuestAvatar(currentUser, avatarId!!, false)
+                if (displayName.equals(context.resources.getString(R.string.nc_guest))) {
+                    holder.binding.avatarView.loadDefaultAvatar(viewThemeUtils)
+                } else {
+                    holder.binding.avatarView.loadGuestAvatar(currentUser, avatarId!!, false)
+                }
             }
 
             else -> {
diff --git a/app/src/main/java/com/nextcloud/talk/adapters/items/ParticipantItem.kt b/app/src/main/java/com/nextcloud/talk/adapters/items/ParticipantItem.kt
index 4b58041ab..e23df8409 100644
--- a/app/src/main/java/com/nextcloud/talk/adapters/items/ParticipantItem.kt
+++ b/app/src/main/java/com/nextcloud/talk/adapters/items/ParticipantItem.kt
@@ -85,6 +85,10 @@ class ParticipantItem(
         setOnlineStateColor(holder)
         holder.binding.nameText.text = model.displayName
 
+        if (model.type == Participant.ParticipantType.GUEST && model.displayName.isNullOrBlank()) {
+            holder.binding.nameText.text = sharedApplication!!.getString(R.string.nc_guest)
+        }
+
         if (adapter!!.hasFilter()) {
             viewThemeUtils.talk.themeAndHighlightText(
                 holder.binding.nameText,
@@ -211,12 +215,11 @@ class ParticipantItem(
             }
 
             Participant.ActorType.GUESTS, Participant.ActorType.EMAILS -> {
-                if (model.displayName.isNullOrEmpty()) {
-                    holder.binding.avatarView.loadDefaultAvatar(viewThemeUtils)
+                val actorName = model.displayName
+                if (!actorName.isNullOrBlank()) {
+                    holder.binding.avatarView.loadFirstLetterAvatar(actorName)
                 } else {
-                    holder.binding.avatarView.loadFirstLetterAvatar(
-                        model.displayName!!.first().toString()
-                    )
+                    holder.binding.avatarView.loadDefaultAvatar(viewThemeUtils)
                 }
             }
 
diff --git a/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingDeckCardViewHolder.kt b/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingDeckCardViewHolder.kt
index 771001cca..17486dc82 100644
--- a/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingDeckCardViewHolder.kt
+++ b/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingDeckCardViewHolder.kt
@@ -157,10 +157,10 @@ class IncomingDeckCardViewHolder(incomingView: View, payload: Any) : MessageHold
     }
 
     private fun setAvatarAndAuthorOnMessageItem(message: ChatMessage) {
-        val author: String = message.actorDisplayName!!
-        if (!TextUtils.isEmpty(author)) {
+        val actorName = message.actorDisplayName
+        if (!actorName.isNullOrBlank()) {
             binding.messageAuthor.visibility = View.VISIBLE
-            binding.messageAuthor.text = author
+            binding.messageAuthor.text = actorName
             binding.messageUserAvatar.setOnClickListener {
                 (payload as? MessagePayload)?.profileBottomSheet?.showFor(message, itemView.context)
             }
diff --git a/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingLinkPreviewMessageViewHolder.kt b/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingLinkPreviewMessageViewHolder.kt
index 53f6506a6..d450213b9 100644
--- a/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingLinkPreviewMessageViewHolder.kt
+++ b/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingLinkPreviewMessageViewHolder.kt
@@ -135,10 +135,10 @@ class IncomingLinkPreviewMessageViewHolder(incomingView: View, payload: Any) :
     }
 
     private fun setAvatarAndAuthorOnMessageItem(message: ChatMessage) {
-        val author: String = message.actorDisplayName!!
-        if (!TextUtils.isEmpty(author)) {
+        val actorName = message.actorDisplayName
+        if (!actorName.isNullOrBlank()) {
             binding.messageAuthor.visibility = View.VISIBLE
-            binding.messageAuthor.text = author
+            binding.messageAuthor.text = actorName
             binding.messageUserAvatar.setOnClickListener {
                 (payload as? MessagePayload)?.profileBottomSheet?.showFor(message, itemView.context)
             }
diff --git a/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingLocationMessageViewHolder.kt b/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingLocationMessageViewHolder.kt
index 69c6e6c29..e5ba4f2d8 100644
--- a/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingLocationMessageViewHolder.kt
+++ b/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingLocationMessageViewHolder.kt
@@ -35,6 +35,7 @@ import com.nextcloud.talk.extensions.loadChangelogBotAvatar
 import com.nextcloud.talk.extensions.loadFederatedUserAvatar
 import com.nextcloud.talk.ui.theme.ViewThemeUtils
 import com.nextcloud.talk.utils.ApiUtils
+import com.nextcloud.talk.utils.ChatMessageUtils
 import com.nextcloud.talk.utils.DateUtils
 import com.nextcloud.talk.utils.UriUtils
 import com.nextcloud.talk.utils.message.MessageUtils
@@ -119,10 +120,10 @@ class IncomingLocationMessageViewHolder(incomingView: View, payload: Any) :
     }
 
     private fun setAvatarAndAuthorOnMessageItem(message: ChatMessage) {
-        val author: String = message.actorDisplayName!!
-        if (!TextUtils.isEmpty(author)) {
+        val actorName = message.actorDisplayName
+        if (!actorName.isNullOrBlank()) {
             binding.messageAuthor.visibility = View.VISIBLE
-            binding.messageAuthor.text = author
+            binding.messageAuthor.text = actorName
             binding.messageUserAvatar.setOnClickListener {
                 (payload as? MessagePayload)?.profileBottomSheet?.showFor(message, itemView.context)
             }
@@ -131,16 +132,7 @@ class IncomingLocationMessageViewHolder(incomingView: View, payload: Any) :
         }
 
         if (!message.isGrouped && !message.isOneToOneConversation && !message.isFormerOneToOneConversation) {
-            binding.messageUserAvatar.visibility = View.VISIBLE
-            if (message.actorType == "guests") {
-                // do nothing, avatar is set
-            } else if (message.actorType == "bots" && message.actorId == "changelog") {
-                binding.messageUserAvatar.loadChangelogBotAvatar()
-            } else if (message.actorType == "bots") {
-                binding.messageUserAvatar.loadBotsAvatar()
-            } else if (message.actorType == "federated_users") {
-                binding.messageUserAvatar.loadFederatedUserAvatar(message)
-            }
+            ChatMessageUtils().setAvatarOnMessage(binding.messageUserAvatar, message, viewThemeUtils)
         } else {
             if (message.isOneToOneConversation || message.isFormerOneToOneConversation) {
                 binding.messageUserAvatar.visibility = View.GONE
diff --git a/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingPollMessageViewHolder.kt b/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingPollMessageViewHolder.kt
index 59b626df8..56b0936bc 100644
--- a/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingPollMessageViewHolder.kt
+++ b/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingPollMessageViewHolder.kt
@@ -142,10 +142,10 @@ class IncomingPollMessageViewHolder(incomingView: View, payload: Any) :
     }
 
     private fun setAvatarAndAuthorOnMessageItem(message: ChatMessage) {
-        val author: String = message.actorDisplayName!!
-        if (!TextUtils.isEmpty(author)) {
+        val actorName = message.actorDisplayName
+        if (!actorName.isNullOrBlank()) {
             binding.messageAuthor.visibility = View.VISIBLE
-            binding.messageAuthor.text = author
+            binding.messageAuthor.text = actorName
             binding.messageUserAvatar.setOnClickListener {
                 (payload as? MessagePayload)?.profileBottomSheet?.showFor(message, itemView.context)
             }
diff --git a/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingTextMessageViewHolder.kt b/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingTextMessageViewHolder.kt
index b3565de23..2a587270c 100644
--- a/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingTextMessageViewHolder.kt
+++ b/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingTextMessageViewHolder.kt
@@ -144,10 +144,10 @@ class IncomingTextMessageViewHolder(itemView: View, payload: Any) :
     }
 
     private fun setAvatarAndAuthorOnMessageItem(message: ChatMessage) {
-        val author: String = message.actorDisplayName!!
-        if (!TextUtils.isEmpty(author)) {
+        val actorName = message.actorDisplayName
+        if (!actorName.isNullOrBlank()) {
             binding.messageAuthor.visibility = View.VISIBLE
-            binding.messageAuthor.text = author
+            binding.messageAuthor.text = actorName
             binding.messageUserAvatar.setOnClickListener {
                 (payload as? MessagePayload)?.profileBottomSheet?.showFor(message, itemView.context)
             }
diff --git a/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingVoiceMessageViewHolder.kt b/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingVoiceMessageViewHolder.kt
index 36155bf09..9413e1720 100644
--- a/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingVoiceMessageViewHolder.kt
+++ b/app/src/main/java/com/nextcloud/talk/adapters/messages/IncomingVoiceMessageViewHolder.kt
@@ -238,10 +238,10 @@ class IncomingVoiceMessageViewHolder(incomingView: View, payload: Any) :
     }
 
     private fun setAvatarAndAuthorOnMessageItem(message: ChatMessage) {
-        val author: String = message.actorDisplayName!!
-        if (!TextUtils.isEmpty(author)) {
+        val actorName = message.actorDisplayName
+        if (!actorName.isNullOrBlank()) {
             binding.messageAuthor.visibility = View.VISIBLE
-            binding.messageAuthor.text = author
+            binding.messageAuthor.text = actorName
             binding.messageUserAvatar.setOnClickListener {
                 (payload as? MessagePayload)?.profileBottomSheet?.showFor(message, itemView.context)
             }
diff --git a/app/src/main/java/com/nextcloud/talk/extensions/ImageViewExtensions.kt b/app/src/main/java/com/nextcloud/talk/extensions/ImageViewExtensions.kt
index 1d70a986c..9411756c0 100644
--- a/app/src/main/java/com/nextcloud/talk/extensions/ImageViewExtensions.kt
+++ b/app/src/main/java/com/nextcloud/talk/extensions/ImageViewExtensions.kt
@@ -305,10 +305,10 @@ fun ImageView.loadNoteToSelfAvatar(): io.reactivex.disposables.Disposable {
     )
 }
 
-fun ImageView.loadFirstLetterAvatar(letter: String): io.reactivex.disposables.Disposable {
+fun ImageView.loadFirstLetterAvatar(name: String): io.reactivex.disposables.Disposable {
     val layers = arrayOfNulls<Drawable>(2)
     layers[0] = ContextCompat.getDrawable(context, R.drawable.ic_launcher_background)
-    layers[1] = createTextDrawable(context, letter.uppercase(Locale.ROOT))
+    layers[1] = createTextDrawable(context, name.trimStart().uppercase(Locale.ROOT))
 
     val layerDrawable = LayerDrawable(layers)
     val data: Any = layerDrawable
diff --git a/app/src/main/java/com/nextcloud/talk/utils/ChatMessageUtils.kt b/app/src/main/java/com/nextcloud/talk/utils/ChatMessageUtils.kt
index 92a8827d8..1f0c5e13f 100644
--- a/app/src/main/java/com/nextcloud/talk/utils/ChatMessageUtils.kt
+++ b/app/src/main/java/com/nextcloud/talk/utils/ChatMessageUtils.kt
@@ -21,8 +21,9 @@ class ChatMessageUtils {
     fun setAvatarOnMessage(view: ImageView, message: ChatMessage, viewThemeUtils : ViewThemeUtils) {
         view.visibility = View.VISIBLE
         if (message.actorType == "guests" || message.actorType == "emails") {
-            if (message.actorDisplayName?.isNotEmpty() == true) {
-                view.loadFirstLetterAvatar(message.actorDisplayName?.first().toString())
+            val actorName = message.actorDisplayName
+            if (!actorName.isNullOrBlank()) {
+                view.loadFirstLetterAvatar(actorName)
             } else {
                 view.loadDefaultAvatar(viewThemeUtils)
             }