Troubleshoot and resolve The system blocked a potential email loop. (WHMCS 8.4 and later) or Blocked Potential Email Loop (WHMCS 8.3 and earlier) errors.
Troubleshoot and resolve last request failed: invalid SASL argument errors.
Troubleshoot and resolve Local Delivery Failed errors.
Troubleshoot and resolve Logon failure: unknown user name or bad password errors.
Troubleshoot and resolve cannot select INBOX, is this a valid transport? errors.
Troubleshoot and resolve Bad Request errors when importing email replies from Microsoft®.
Troubleshoot and resolve Connection unsuccessful errors when importing email replies from Microsoft.