Troubleshooting mailbox connection issues
IMAP connection issues are the most common support topic. This guide covers the errors you are most likely to encounter and how to resolve them.
Authentication failed
This is the #1 issue. It almost always means the password is wrong.
Most common cause: you need an app-specific password
If you have two-factor authentication enabled on your email account (and you should), your regular login password will not work for IMAP. You need to generate an app-specific password. See IMAP connection details per provider for instructions.
Other causes
- Typo in email address — Make sure the username is your full email address, not just the local part
- Password changed — If you recently changed your email password, update it in Cleanbox too
- Account locked — Some providers temporarily lock accounts after multiple failed login attempts. Wait 15-30 minutes and try again.
- Google Workspace: admin disabled IMAP — Your organization administrator may have disabled IMAP access. Contact your IT admin.
Connection timeout
Cleanbox could not reach the IMAP server within the allowed time.
- Wrong host or port — Verify the IMAP server address and port. Standard is port 993 with SSL/TLS. See the IMAP settings table.
- Server temporarily down — Your email provider may be experiencing issues. Check their status page and try again later.
- Firewall blocking — Rare for cloud-hosted email, but if you self-host, make sure port 993 is open.
IMAP not enabled
Some providers disable IMAP by default. You need to enable it manually:
- Gmail — Settings → See all settings → Forwarding and POP/IMAP → Enable IMAP
- Yahoo — Settings → More Settings → Mailbox access → Enable IMAP
- Outlook/Microsoft 365 — IMAP is enabled by default. If disabled, your admin may have turned it off in Exchange settings.
Sync is slow
Initial contact discovery scans your existing emails. For large mailboxes (50,000+ emails), this can take several minutes. The scan runs in the background — you can navigate away and come back. Your dashboard updates automatically when complete.
Folder not found
If you configured a custom destination folder and it was deleted from your email client, delivery will fail. Fix this by:
- Going to your mailbox settings
- Changing the destination folder to INBOX or creating a new folder
- Retrying any failed deliveries from the messages page
Mailbox disconnects periodically
If your mailbox keeps going inactive:
- App-specific password expired — Some providers expire app passwords after a period. Generate a new one.
- Provider revoked access — If your provider detected unusual activity, they may have revoked IMAP access. Re-authorize from your provider settings.
- Password changed elsewhere — If you changed your password from another device, update it in Cleanbox.
Still stuck?
If none of the above resolves your issue, contact our support team with:
- Your email provider name
- The exact error message you see
- Whether you are using an app-specific password
