1. Validate configuration in SMACC

Verify the following settings are correct:

• • SMTP server hostname or IP address
  • Port number
  • TLS/SSL enabled or disabled according to server requirements
  • Correct sender email address format
  • Valid authentication credentials (username + password)

2. Test external SMTP connectivity

Use a simple authenticated test with a known working account. Examples:

PowerShell

Send-MailMessage -From "user@example.com" -To "recipient@example.com" -Subject "SMTP Test" -Body "Test" -SmtpServer "smtp.example.com" -Port 587 -UseSsl -Credential (Get-Credential)

curl

curl --url "smtp://smtp.example.com:587" \

 --ssl-reqd \

 --mail-from "user@example.com" \

 --mail-rcpt "recipient@example.com" \

 --upload-file email.txt \

 --user "user@example.com:password"

If basic tests fail, collect SMTP server logs for detailed errors.

3. Review SMTP server policies

• • Ensure sender address is allowed to relay email
  • Confirm authentication method is supported (e.g., no anonymous send)
  • Check for syntax and illegal command sequence issues, such as:
    • 500 syntax error
    • 503 illegal command sequence

These indicate policy or security requirements are not satisfied.

4. Check network/Security controls

• • Verify no firewall, proxy, or antivirus product is terminating SMTP traffic
  • If Zero Trust or email security scanning is enabled, safelist the beacon/report exporter server

Involve the network/security team to review logs for dropped connections. If connectivity and configuration are correct, involve the SMTP server administrator for deeper analysis.

5. Optional: Handle large reports

If errors occur only for large scheduled reports:

• • Reduce report size, or
  • Request an increased maximum message size on the SMTP server

Once SMTP configuration and network communication are correctly aligned, scheduled reports export successfully and emails are delivered without connection errors.