Guides
Troubleshooting
Fix email delivery problems
SMTP configuration
- Confirm host, port, and encryption match your provider's documented values.
- Use an app password where required, not your account password.
- Run the Send test email on Email & SMTP to isolate the relay.
Emails land in spam
- Verify SPF and DKIM records include your sending domain.
- Keep the from-address consistent with the relay.
- Avoid spammy subject lines: see Email templates.
Delayed or intermittent delivery
- Respect your provider's daily sending limits.
- Batch sends instead of drip-sending in a burst.
- Check the request's audit trail for delivery timestamps.
Still failing
Confirm your SMTP account can send from a mail client directly. If it works there but not in Undersign, contact support with your settings (password redacted) and the test error.
What happens next?
Email delivery is usually a config or reputation problem, not an app problem. The detailed reference is Email & SMTP troubleshooting.