Introduction

When Roundcube sends mail but nothing shows up in the Sent folder after a server move, the problem is usually not the message itself. In most cases, the message was sent successfully and the failure is in how Roundcube or the IMAP server maps, subscribes to, or stores the sent-mail copy on the new server. Migrations often change folder names, namespaces, delimiters, or special folder detection, so Roundcube keeps looking for the old Sent path while the new server saves mail somewhere else. Treat this as a sent-folder mapping problem before assuming mail is being lost.

Symptoms

  • Messages send successfully from Roundcube, but no copy appears in Sent
  • Old sent mail is visible, but new sent messages do not show up after the server move
  • Roundcube shows multiple possible Sent folders such as Sent, Sent Items, or INBOX.Sent
  • The issue appeared right after migration, server replacement, or mail platform change
  • Another mail client shows the sent copy in a different folder than Roundcube
  • Only some mailboxes are affected while others still save to Sent normally

Common Causes

  • Roundcube is still mapped to the old Sent folder path from the previous server
  • The correct Sent folder exists but is not subscribed in IMAP after migration
  • The new IMAP server uses a different namespace, delimiter, or special-use folder configuration
  • A second Sent-style folder was created during migration and Roundcube is reading the wrong one
  • The mailbox can send mail, but the IMAP folder lacks the right permissions or write behavior
  • Cached Roundcube preferences or old folder metadata survived the server move

Step-by-Step Fix

  1. Send a fresh test message from Roundcube and confirm whether the message is actually delivered, because if delivery works but the sent copy is missing, you can focus on folder mapping instead of outbound mail transport.
  2. Open Roundcube settings and verify which folder is assigned as the Sent folder for that mailbox, because migrations often leave Roundcube pointing to the old folder name even after the server now uses a different path.
  3. Compare the visible folder list for duplicates such as Sent, Sent Items, INBOX.Sent, or localized folder names, because a server move can create a second folder that holds the new sent copies while Roundcube keeps displaying the old one.
  4. Check IMAP subscriptions for the mailbox and subscribe the correct Sent folder if needed, because Roundcube can fail to display the active folder cleanly when the mailbox copy exists but the folder was never subscribed after migration.
  5. Verify the IMAP namespace and folder delimiter on the new server, because a mailbox that used to store Sent under one path style can move to another and break the folder mapping Roundcube saved previously.
  6. Confirm the mail server is marking or exposing the correct special-use sent folder, because Roundcube relies on the server-side folder model more reliably when the new platform advertises the right Sent mailbox instead of leaving multiple candidates.
  7. Check mailbox permissions, quota state, and ownership if the server should save a sent copy but does not, because a folder that cannot be written cleanly can make Roundcube appear to send mail without ever storing the message in Sent.
  8. Clear stale Roundcube preferences or test the same mailbox with a clean Roundcube session if the mapping still looks wrong, because cached folder settings from the old server can survive the migration and keep forcing the wrong Sent folder.
  9. Re-test from Roundcube and from another IMAP client after each change and document which folder receives the sent copy, because matching behavior across clients confirms the mailbox mapping is fixed while a mismatch points to a client-specific Roundcube problem.