Email Integration
Troubleshooting Email Delivery Issues
Diagnose and resolve common delivery problems including spam filters, bounced messages, SMTP authentication timeouts, and SPF/DKIM/DMARC DNS records.
If your clients report that they have not received an invoice notification or message sent from Flanceflow, delivery blockers are almost always tied to domain authentication records (SPF, DKIM, DMARC) or spam filtering algorithms. Follow this systematic troubleshooting checklist to ensure your emails reach your clients’ primary inbox every time.
Step-by-step email diagnostic procedure
- Confirm the recipient email: Open the client profile or invoice details to verify there are no typos in the client email address.
- Check your delivery logs: In Flanceflow, navigate to "Settings" > "Email & Notifications" and review the "Recent Delivery Logs" section for bounce notices or SMTP error codes.
- Check Spam and Junk folders: Have the client search their spam, promotions, or junk folder for your sender name or invoice number.
- Verify SPF records: If using custom SMTP, verify your custom domain’s DNS TXT record includes your email provider’s SPF mechanism (e.g., `include:zoho.com ~all` or `include:_spf.google.com ~all`).
- Verify DKIM authentication: Ensure DKIM public keys are published in your domain’s DNS manager and your mail host has DKIM signing enabled.
- Check DMARC alignment: For custom SMTP servers, ensure the "From" display address matches the authenticated domain exactly to prevent strict DMARC rejection policies (`p=reject`).
- Default mailer whitelisting: If using the default Flanceflow mail delivery system, advise clients to whitelist `noreply@flanceflow.com` in their corporate firewall or email client.
- Run a live SMTP test: Go to "Settings" > "Email & Notifications" and click "Send Test Email" to inspect real-time connection response logs.
Common email delivery errors & fixes
| Error / Symptom | Root cause | Resolution step |
|---|---|---|
| Invoices landing in spam | Missing or misconfigured SPF/DKIM/DMARC records on custom domain | Check DNS TXT records; ensure From address matches authenticated domain. |
| "SMTP 535 Authentication Failed" | Incorrect password or 2FA blocking login | Generate a specialized App Password in Zoho, Google, or Microsoft account. |
| "SMTP Connection Timed Out" | Firewall blocking outbound port 587 or 465 | Switch encryption to Port 465 (SSL) or verify server hostname spelling. |
| Client firewall drops email | Strict enterprise email gateway rules (Proofpoint/Mimecast) | Ask client IT to whitelist your domain or default sender `noreply@flanceflow.com`. |
| OAuth Token Expired | Google account password changed or permission revoked | Go to Settings > Email and click "Reconnect with Google". |
Delivery optimization tips
- Test with Mail-Tester: Send a test email from Flanceflow to `mail-tester.com` to receive a detailed spam score and identify missing DNS signatures.
- Avoid spam-trigger words: Keep subject lines descriptive (e.g., "Invoice #104 - Mobile UI Design") and avoid aggressive phrases like "PAY IMMEDIATELY $quot; in email subject lines.
- Multi-channel backup: If an enterprise spam filter is unusually strict, copy the invoice public link and paste it into your active Slack or WhatsApp thread with the client.
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