diff --git a/app/core/src/main/java/com/fsck/k9/controller/MessagingController.java b/app/core/src/main/java/com/fsck/k9/controller/MessagingController.java
index 9996054bfb8..620cf0cf937 100644
--- a/app/core/src/main/java/com/fsck/k9/controller/MessagingController.java
+++ b/app/core/src/main/java/com/fsck/k9/controller/MessagingController.java
@@ -1886,8 +1886,13 @@ public void expunge(Account account, long folderId) {
     public void deleteDraft(final Account account, long id) {
         LocalFolder localFolder = null;
         try {
+            Long folderId = account.getDraftsFolderId();
+            if (folderId == null) {
+                Timber.w("No Drafts folder configured. Can't delete draft.");
+                return;
+            }
+
             LocalStore localStore = localStoreProvider.getInstance(account);
-            long folderId = account.getDraftsFolderId();
             localFolder = localStore.getFolder(folderId);
             localFolder.open();
             String uid = localFolder.getMessageUidById(id);
@@ -2135,8 +2140,13 @@ public void emptyTrash(final Account account, MessagingListener listener) {
             public void run() {
                 LocalFolder localFolder = null;
                 try {
+                    Long trashFolderId = account.getTrashFolderId();
+                    if (trashFolderId == null) {
+                        Timber.w("No Trash folder configured. Can't empty trash.");
+                        return;
+                    }
+
                     LocalStore localStore = localStoreProvider.getInstance(account);
-                    long trashFolderId = account.getTrashFolderId();
                     localFolder = localStore.getFolder(trashFolderId);
                     localFolder.open();
                     String trashFolderServerId = localFolder.getServerId();
@@ -2567,8 +2577,13 @@ public void deleteAccount(Account account) {
     public Message saveDraft(final Account account, final Message message, long existingDraftId, String plaintextSubject, boolean saveRemotely) {
         LocalMessage localMessage = null;
         try {
+            Long draftsFolderId = account.getDraftsFolderId();
+            if (draftsFolderId == null) {
+                throw new IllegalStateException("No Drafts folder configured");
+            }
+
             LocalStore localStore = localStoreProvider.getInstance(account);
-            LocalFolder localFolder = localStore.getFolder(account.getDraftsFolderId());
+            LocalFolder localFolder = localStore.getFolder(draftsFolderId);
             localFolder.open();
 
             if (existingDraftId != INVALID_MESSAGE_ID) {
diff --git a/app/core/src/main/java/com/fsck/k9/search/AccountSearchConditions.kt b/app/core/src/main/java/com/fsck/k9/search/AccountSearchConditions.kt
index 70c5731ecc7..bf19c3d3d2d 100644
--- a/app/core/src/main/java/com/fsck/k9/search/AccountSearchConditions.kt
+++ b/app/core/src/main/java/com/fsck/k9/search/AccountSearchConditions.kt
@@ -75,7 +75,9 @@ class AccountSearchConditions {
         excludeSpecialFolder(search, account.spamFolderId)
         excludeSpecialFolder(search, account.outboxFolderId)
         excludeSpecialFolder(search, account.sentFolderId)
-        search.or(SearchCondition(SearchField.FOLDER, Attribute.EQUALS, account.inboxFolderId!!.toString()))
+        account.inboxFolderId?.let { inboxFolderId ->
+            search.or(SearchCondition(SearchField.FOLDER, Attribute.EQUALS, inboxFolderId.toString()))
+        }
     }
 
     /**
@@ -97,7 +99,9 @@ class AccountSearchConditions {
         excludeSpecialFolder(search, account.trashFolderId)
         excludeSpecialFolder(search, account.spamFolderId)
         excludeSpecialFolder(search, account.outboxFolderId)
-        search.or(SearchCondition(SearchField.FOLDER, Attribute.EQUALS, account.inboxFolderId.toString()))
+        account.inboxFolderId?.let { inboxFolderId ->
+            search.or(SearchCondition(SearchField.FOLDER, Attribute.EQUALS, inboxFolderId.toString()))
+        }
     }
 
     private fun excludeSpecialFolder(search: LocalSearch, folderId: Long?) {
diff --git a/app/ui/src/main/java/com/fsck/k9/activity/MessageList.java b/app/ui/src/main/java/com/fsck/k9/activity/MessageList.java
index 05340c0c7e2..38ce2a50123 100644
--- a/app/ui/src/main/java/com/fsck/k9/activity/MessageList.java
+++ b/app/ui/src/main/java/com/fsck/k9/activity/MessageList.java
@@ -1244,7 +1244,8 @@ public void openMessage(MessageReference messageReference) {
         Account account = preferences.getAccount(messageReference.getAccountUuid());
         long folderId = messageReference.getFolderId();
 
-        if (folderId == account.getDraftsFolderId()) {
+        Long draftsFolderId = account.getDraftsFolderId();
+        if (draftsFolderId != null && folderId == draftsFolderId) {
             MessageActions.actionEditDraft(this, messageReference);
         } else {
             if (messageListFragment != null) {
diff --git a/app/ui/src/main/java/com/fsck/k9/ui/messageview/MessageViewFragment.java b/app/ui/src/main/java/com/fsck/k9/ui/messageview/MessageViewFragment.java
index 012bbdfc9b3..45e7efee619 100644
--- a/app/ui/src/main/java/com/fsck/k9/ui/messageview/MessageViewFragment.java
+++ b/app/ui/src/main/java/com/fsck/k9/ui/messageview/MessageViewFragment.java
@@ -321,8 +321,8 @@ private void delete() {
         }
     }
 
-    public void onRefile(long dstFolderId) {
-        if (!mController.isMoveCapable(mAccount)) {
+    public void onRefile(Long dstFolderId) {
+        if (dstFolderId == null || !mController.isMoveCapable(mAccount)) {
             return;
         }
         if (!mController.isMoveCapable(mMessageReference)) {
@@ -331,7 +331,7 @@ public void onRefile(long dstFolderId) {
             return;
         }
 
-        if (dstFolderId == mAccount.getSpamFolderId() && K9.isConfirmSpam()) {
+        if (dstFolderId.equals(mAccount.getSpamFolderId()) && K9.isConfirmSpam()) {
             destinationFolderId = dstFolderId;
             showDialog(R.id.dialog_confirm_spam);
         } else {