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Mailbox Connection Errors

Understanding why your mailbox is disconnected and how to fix it

What Does “Disconnected” Mean?

A disconnected mailbox means Superkabe cannot send or receive emails through this account. The SMTP (sending) or IMAP (receiving) connection to your email provider has failed.

Impact: Disconnected mailboxes are automatically paused across all campaigns. Leads assigned to this mailbox are rotated to other active mailboxes until the connection is restored.

How Connection Status Works

  1. 1

    Sync with Sending Platform

    Superkabe syncs your mailbox data from your connected sending platform, which tests SMTP and IMAP connections.

  2. 2

    Connection Check (First Priority)

    Before any bounce rate or risk analysis, Superkabe checks if SMTP and IMAP are working.

  3. 3

    Status Assignment

    If either connection fails, the mailbox is marked Disconnected and paused immediately. If both pass, normal health assessment continues.

Common Connection Errors

🔑

Google OAuth Token Expired / Revoked

Error: “Failed to refresh Google token: invalid_grant”

Google requires periodic re-authorization. This happens when:

  • • The Google account password was changed
  • • OAuth access was revoked from Google Security settings
  • • The token naturally expired after 6 months of inactivity
  • • Two-factor authentication settings were changed

✅ How to Fix

  1. 1. Go to your sending platform's Email Accounts settings
  2. 2. Find the affected mailbox and click Reconnect
  3. 3. Complete the Google OAuth authorization flow
  4. 4. Return to Superkabe and trigger a Manual Sync
📄 Google: Third-party app access🔒 Google Account Security
🔐

Authentication Failed

Error: “Authentication failed” or “Invalid credentials”

The email password or app password is incorrect or has been changed.

✅ How to Fix

  1. 1. Go to your sending platform's Email Accounts settings
  2. 2. Update the mailbox password/app password
  3. 3. If using Google with 2FA, generate a new App Password
  4. 4. If using Microsoft with 2FA, generate a new App Password
  5. 5. Return to Superkabe and trigger a Manual Sync
📄 Google: App Passwords📄 Microsoft: App Passwords
🚫

Connection Refused / Server Unreachable

Error: “Connection refused” or “ECONNREFUSED”

The SMTP or IMAP server is not accepting connections. This usually means the mail server is down or misconfigured.

✅ How to Fix

  1. 1. Verify your email provider's SMTP/IMAP server addresses in your sending platform
  2. 2. Check if your email provider is experiencing an outage
  3. 3. Confirm DNS records (MX, A) are resolving correctly
  4. 4. If using a custom mail server, check firewall rules for ports 587 (SMTP) and 993 (IMAP)
📄 Google: SMTP & IMAP Settings📄 Microsoft: SMTP & IMAP Settings
⏱️

Connection Timeout

Error: “Connection timed out” or “ETIMEDOUT”

The mail server is not responding within the expected timeframe. This is usually a temporary issue.

✅ How to Fix

  1. 1. Wait 15-30 minutes and trigger a Manual Sync in Superkabe
  2. 2. Check your email provider's status page for outages
  3. 3. If persistent, try reconnecting the account in your sending platform
🔒

SSL/TLS Certificate Error

Error: “Certificate error” or “SSL handshake failed”

The mail server's SSL certificate is invalid, expired, or the wrong encryption port is being used.

✅ How to Fix

  1. 1. In your sending platform, verify the SMTP port (typically 587 with STARTTLS or 465 with SSL)
  2. 2. Verify the IMAP port (typically 993 with SSL)
  3. 3. Ensure the server hostname matches the certificate (e.g., smtp.gmail.com, not an IP address)
  4. 4. If using a custom mail server, renew the SSL certificate

Provider-Specific Guides

📧

Google Workspace / Gmail

Most Google connection issues are caused by OAuth token expiration or changes to your Google account security settings.

→ Managing third-party app access→ Creating App Passwords (2FA accounts)→ Google SMTP relay settings→ Google Account Security settings
📬

Microsoft 365 / Outlook

Microsoft connection issues commonly stem from app password expiration or changes to multi-factor authentication (MFA) settings.

→ Managing App Passwords (2FA accounts)→ POP, IMAP, and SMTP settings→ Enabling SMTP AUTH for mailboxes→ Microsoft Account Security settings

General Troubleshooting Steps

  1. 1

    Check Your Sending Platform First

    Go to your sending platform's email accounts section. If the account shows as disconnected there too, the issue is at the provider level.

  2. 2

    Reconnect in Your Platform

    Click “Reconnect” or re-enter credentials for the affected mailbox. For OAuth accounts (Google), complete the authorization flow again.

  3. 3

    Sync in Superkabe

    After fixing the connection in your sending platform, go to Superkabe → Settings and click Manual Sync. This will re-fetch connection status and update the mailbox.

  4. 4

    Verify in Superkabe

    Go to Mailboxes and confirm the status changed from “Disconnected” to “Connected”. The mailbox will automatically resume in its campaigns.

Still Need Help?

If you've followed the steps above and the mailbox is still disconnected:

  • • Check the exact error message shown in the diagnostic card on the Mailboxes page
  • • Contact your email provider's support team with the error details
  • • Reach out to support@superkabe.com and we'll help investigate

Related Help Articles

→ Why Is My Campaign Paused?→ How Auto-Healing Works (5-Phase Pipeline)→ Platform Integration Guides