Who This Is For / When to Use
This guide is for users configuring an SMTP service in Kyrios who experience authentication failures, undelivered emails, connection timeouts, or provider-specific restrictions.
Where do I configure SMTP services in Kyrios?
SMTP services are configured from the Email Services section inside Kyrios settings.
Steps:
Go to Settings → Email Services.
Select the SMTP Service tab.
Click + Add Service to configure a new provider.
Choose your SMTP provider from the list.
How do I set up Gmail or Google Workspace as my SMTP provider?
Gmail and Google Workspace require authentication and correct SMTP server settings to send emails securely.
Steps:
Navigate to Settings → Email Services → Add Service.
Select Gmail as the SMTP provider.
Complete the authentication flow as prompted.
Send a test email to confirm the connection.
If setup fails:
Confirm the correct SMTP server and port are used.
Ensure account security settings allow SMTP access.
Why does Microsoft 365 show an “Authentication Unsuccessful” error?
Microsoft requires SMTP Authentication to be explicitly enabled, even if multi-factor authentication is disabled.
How to fix:
Log into the Microsoft 365 admin center.
Enable SMTP Authentication for the mailbox.
Verify the SMTP server and port settings.
Send a test email from Kyrios.
If errors continue, Microsoft may be blocking third-party access at the tenant level.
Why are emails not sending with Amazon SES?
Amazon SES requires correct IAM credentials and production access for successful delivery.
Checklist:
Use the correct SES SMTP endpoint.
Use Port 465 (SSL).
Verify IAM username and password.
Confirm the SES account is out of sandbox mode.
Test delivery after each correction.
Why can’t I use a free email address as my SMTP provider?
Free email providers limit sending volume and may block automated or bulk email traffic.
Recommended fixes:
Use a professional domain-based email address.
Configure SPF, DKIM, and DMARC records.
Switch to a dedicated email service for higher volume.
Using a dedicated SMTP provider improves deliverability and sender reputation.
My emails are not being delivered after SMTP setup. What should I check?
Delivery failures usually result from DNS misconfiguration, provider limits, or incorrect SMTP settings.
Steps to verify:
Confirm SPF, DKIM, and DMARC records exist and are valid.
Verify the SMTP host and port.
Check daily sending limits with your provider.
Review email content for spam triggers.
What SMTP ports should I use?
SMTP ports vary by provider and security protocol.
Common ports:
Gmail / Google Workspace: 465 (SSL), 587 (TLS)
Microsoft 365: 587 (TLS)
Amazon SES: 465 (SSL)
Mailgun / SendGrid: 587 (TLS)
Using an incorrect port will prevent connection.
How can I test if my SMTP integration works?
Kyrios includes a built-in test email feature.
Steps:
Save your SMTP configuration.
Click Send Test Email.
Confirm delivery to the test inbox.
If the test fails, recheck credentials and ports.
Why do I get a “Connection Timed Out” error?
Timeout errors usually mean outbound SMTP traffic is blocked by your network or hosting provider.
How to fix:
Avoid Port 25, which is commonly blocked.
Switch to Port 587 or 465.
Check firewall or antivirus restrictions.
Confirm outbound mail is allowed by your host.
If needed, whitelist the SMTP provider’s IPs.
Common Issues and Fixes
Authentication failed: Enable SMTP authentication at the provider level.
Emails not delivered: Verify DNS records and sending limits.
Timeout errors: Change ports or check firewall rules.
Low deliverability: Use a dedicated sending domain and provider.