diff --git a/app/courrier/page.tsx b/app/courrier/page.tsx
index c8da2b8a..4b134c61 100644
--- a/app/courrier/page.tsx
+++ b/app/courrier/page.tsx
@@ -582,25 +582,28 @@ export default function CourrierPage() {
         account.folders = ['INBOX', 'SENT', 'DRAFTS', 'TRASH'];
       }
 
+      // Remove account prefix if present
+      const baseFolder = folder.includes(':') ? folder.split(':')[1] : folder;
+
       // Use the exact folder name from the account's folders list
-      if (!account.folders.includes(folder)) {
-        console.warn(`Folder ${folder} not found in account ${accountId}, defaulting to INBOX`);
+      if (!account.folders.includes(baseFolder)) {
+        console.warn(`Folder ${baseFolder} not found in account ${accountId}, defaulting to INBOX`);
         toast({
           title: "Folder not found",
-          description: `The folder ${folder} does not exist for this account. Defaulting to INBOX.`,
+          description: `The folder ${baseFolder} does not exist for this account. Defaulting to INBOX.`,
           variant: "destructive",
         });
         folder = 'INBOX'; // Default to INBOX if folder doesn't exist
       }
 
-      // Update selected folders state
+      // Update selected folders state with the full prefixed folder name
       setSelectedFolders(prev => ({
         ...prev,
-        [accountId]: folder
+        [accountId]: `${accountId}:${folder}`
       }));
 
-      // Change to the selected folder
-      changeFolder(folder, accountId);
+      // Change to the selected folder with account prefix
+      changeFolder(`${accountId}:${folder}`, accountId);
     } else {
       // For all accounts view, use the original folder name
       changeFolder(folder, accountId);
diff --git a/lib/services/email-service.ts b/lib/services/email-service.ts
index 861f1577..c938b169 100644
--- a/lib/services/email-service.ts
+++ b/lib/services/email-service.ts
@@ -608,7 +608,12 @@ export async function getMailboxes(client: ImapFlow, accountId?: string): Promis
   try {
     const mailboxes = await client.list();
     
-    // Return the exact folder names from IMAP without any mapping
+    // If we have an accountId, prefix the folder names to prevent namespace collisions
+    if (accountId) {
+      return mailboxes.map(mailbox => `${accountId}:${mailbox.path}`);
+    }
+    
+    // For backward compatibility, return unprefixed names when no accountId
     return mailboxes.map(mailbox => mailbox.path);
   } catch (error) {
     console.error('Error fetching mailboxes:', error);