Work through these in order. Most SMTP problems are a wrong port, a wrong username, or a sender address the provider hasn’t verified.
1. Run Test Connection #
Open White Label > Email Configs > SMTP Connectivity and click Test Connection. A working setup returns SMTP Connected. Anything else points to the host, port, encryption or credentials.
2. Check the usual mistakes #
| Symptom | Likely cause |
|---|---|
| Connection times out | Wrong port, or the port is blocked. Try 465 with SSL or 587 with STARTTLS. |
| Authentication fails | Wrong password, or a provider that needs an app password rather than the mailbox password. On AWS SES, the username must be the SMTP username starting with AKIA…, and the From E-Mail must be a separately verified address. |
| Authentication still fails with correct details | Set SMTP Auth Mode to LOGIN or PLAIN instead of Default (automatic). |
| Test passes but mail never arrives | The provider is rejecting the sender. Verify the From E-Mail with your provider and add SPF and DKIM records to your domain. |
| Some emails arrive, bulk sends stop midway | You are exceeding your provider’s rate limit. Pick a lower SMTP Provider Profile. |
3. Has your SMTP been switched off automatically? #
To protect your mail account from being locked by the provider, SMTP sending is disabled automatically after five consecutive authentication failures, and a notification email is sent to your registered reseller address. While it is disabled, your users receive no emails at all, including login OTPs and signup codes, so fix it as soon as you see that notice.
To restore it: open the SMTP Connectivity section, correct the credentials, and run Test Connection. A successful test clears the failure count and re-enables sending.
4. Still stuck #
Contact support with the exact error from Test Connection, your SMTP host and port, and the time of a failed send, so the mail logs for your account can be checked.