TroubleshootingCopy Anchor Link

Solutions for common issues when sending email through NorthRelay. If your issue is not covered here, use the diagnostic tools in your Dashboard or contact support.

Connection IssuesCopy Anchor Link

"Connection refused" on port 587Copy Anchor Link

Your network may be blocking outbound SMTP connections.

1. Test connectivity from your server:

   Copy Text

   telnet smtp.north-pipe.ca 587

2. If the connection times out, your firewall or hosting provider is blocking port 587. Contact your hosting provider or network administrator to allow outbound TCP on port 587.
3. As a fallback, try port 465 (implicit TLS):

   Copy Text

   telnet smtp.north-pipe.ca 465

"Connection timed out"Copy Anchor Link

• Verify the hostname is exactly smtp.north-pipe.ca (not smtp.northrelay.ca)
• Check that DNS resolution works: nslookup smtp.north-pipe.ca
• Some cloud providers (AWS, GCP) restrict outbound SMTP by default. You may need to request SMTP access or use an alternative port.

TLS handshake failureCopy Anchor Link

• Ensure your client supports TLS 1.2 or later
• Use STARTTLS on port 587 (not raw TLS)
• For port 465, use implicit TLS (your client should connect with TLS directly)
• Test the TLS connection manually:

  Copy Text

  openssl s_client -connect smtp.north-pipe.ca:587 -starttls smtp

Authentication ErrorsCopy Anchor Link

"535 Authentication failed"Copy Anchor Link

Your credentials are incorrect. Double-check:

1. Username must be your full NorthRelay account email (e.g., you@example.com), not a custom domain address
2. Password must be a valid API key starting with nr_live_
3. The API key must be active — check Dashboard → API Keys to confirm it has not been revoked
4. Copy the API key again; whitespace or trailing characters can cause failures

"553 Authentication required"Copy Anchor Link

You are trying to send without authenticating first. Ensure your SMTP client is configured to use authentication with LOGIN or PLAIN mechanism.

"API key format invalid"Copy Anchor Link

API keys follow the format nr_live_xxxxxxxxxxxx. If your key does not start with nr_live_, it may be a test key or an old key format. Generate a new key from Dashboard → API Keys.

Delivery ProblemsCopy Anchor Link

Emails landing in spamCopy Anchor Link

This is almost always caused by missing or incorrect DNS authentication records.

1. Set up SPF — Add a TXT record to your domain:

   Copy Text

   v=spf1 include:_spf.north-pipe.ca -all

2. Verify DKIM — DKIM is auto-configured when you verify your domain in the dashboard. Confirm the DKIM record is published:

   Copy Text

   dig TXT default._domainkey.yourdomain.com

3. Add DMARC — Add a TXT record at _dmarc.yourdomain.com:

   Copy Text

   v=DMARC1; p=quarantine; rua=mailto:dmarc@yourdomain.com

See the full DNS Setup Guide for step-by-step instructions.

Domain not verifiedCopy Anchor Link

You must verify domain ownership before sending from a custom domain (Pro tier and above).

1. Go to Dashboard → Domains
2. Add your domain and follow the verification steps
3. Add the required DNS records (TXT verification record)
4. Click Verify — DNS propagation can take up to 48 hours

High bounce rateCopy Anchor Link

A bounce rate above 5% can harm your sender reputation.

• Remove invalid addresses from your mailing list
• Use double opt-in for new subscribers
• Check the bounce reasons in Dashboard → Email Logs
• Monitor your reputation score at Dashboard → Reputation

Emails rejected by recipient serverCopy Anchor Link

If the recipient's mail server is rejecting your email:

• Check for a specific error code in the bounce message (visible in Email Logs)
• Run the Pre-Flight Check tool: Dashboard → Tools → Pre-Flight Check
• Check the Blocklist Monitor: Dashboard → Tools → Blocklist — this scans 13 industry-standard RBL providers

Rate LimitingCopy Anchor Link

"451 4.7.1 Rate limit exceeded"Copy Anchor Link

You have hit your plan's sending quota.

1. Check current usage at Dashboard → Billing (the usage bar shows percentage consumed)
2. Warnings appear at 80% and 100% of your quota
3. Quota resets on the 1st of each calendar month

To increase your quota, upgrade your plan at Dashboard → Billing.

Temporary rate limiting (421)Copy Anchor Link

A 421 response means the server is temporarily throttling your connection. This can happen during high-volume sends.

• Wait 30-60 seconds and retry
• Implement exponential backoff in your application
• Spread large sends over a longer time window

Email RejectedCopy Anchor Link

Spam content detectedCopy Anchor Link

NorthRelay scans outbound email for content that may trigger spam filters. If your email is rejected:

• Avoid excessive use of ALL CAPS, exclamation marks, and spam trigger words
• Ensure the HTML-to-text ratio is reasonable (include a plain text version)
• Do not use URL shorteners in email body

Blocked recipient (suppression list)Copy Anchor Link

If a recipient previously bounced or marked your email as spam, they may be on your suppression list.

• Check the suppression list in Dashboard → Email Logs → Suppressions
• Remove the address from the suppression list if you believe the issue is resolved
• Re-sending to suppressed addresses without removing them first will result in a silent drop

Diagnostic ToolsCopy Anchor Link

NorthRelay provides built-in tools to diagnose sending issues:

Getting HelpCopy Anchor Link

If you are still experiencing issues after trying the steps above:

1. Check the Dashboard → Email Logs for detailed error messages
2. Run the diagnostic tools listed above
3. Review the DNS Setup Guide and SMTP Configuration guides
4. Contact support at support@northrelay.ca with your account email and the message ID from the Email Logs