Troubleshooting email delivery in Email Security.cloud product
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Troubleshooting email delivery in Email Security.cloud product

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Article ID: 169843

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Updated On:

Products

Email Security.cloud

Issue/Introduction

Learn how to troubleshoot the following email delivery issues for Symantec Email Security.cloud:

  • Inbound email messages not blocked or received
  • Outbound email messages blocked or not sent
  • Inbound or outbound emails delayed
  • Intermittent email failures or errors
  • Transport Layer Security (TLS) failures

Also, learn how to use the Email Delivery Troubleshooting tool.

Resolution

Contents

Email Delivery Troubleshooting tool:

Use the Email Delivery Troubleshooting tool to diagnose common issues that affect email delivery to and from both internal and external email addresses and domains.

The tool prompts you to specify information about the problem you are having, runs checks based on the information you provide, and then displays results that you can use to solve the problem

To run the Email Delivery Troubleshooting Tool

  1. In the Symantec.cloud portal, click Tools > Email Delivery Troubleshooting Tool.
  2. For Select what type of problem you are experiencing, respond by selecting one of the following:
    • Problems receiving mail
    • Problems sending email
    • Problems receiving too much spam
  3. For Which recipients are affected/Who is having this problem, respond by selecting one of the following:
    • Only one of my addresses
    • Only one of my domains
    • My whole organization
  4. Respond to any additional prompts if asked, such as the problematic address or domain, the domain and address of the recipient experiencing issues, or the domain and address of the sender who is experiencing issues.
  5. Specify whether to receive your results on-screen or by email. If you select email, enter the email address to send the results to.
  6. Click Run checks.

Note: If you select to have results sent via email, no further information will be displayed on the screen after you click the Run checks button. Instead, the results of the checks are sent to the specified email address.

For more information, see the following:

Inbound email(s) not blocked:

If one or more inbound emails are not blocked in your environment, review the following:

Inbound emails(s) not received:

To look for issues, use the Email Delivery Troubleshooting Tool (under Tools > Email Delivery Troubleshooting Tool in the Symantec.cloud portal).

  • Can you find the emails using Email Track and Trace (under Tools > Email Track and Trace)?
    • If not, check the recipient domain in DNS to confirm that the MX records match what was provided when the domain was provisioned.
  • Is mail being routed to the correct location when we attempt to deliver it?
    • Use Email Track and Trace (under Tools > Email Track and Trace)
    •  to confirm the status of delivery.
      • If Delivered - Is the IP the expected server?
      • If Retrying the IP may show as 0.0.0.0 this means we weren't able to successfully connect to any servers.
    • Make sure the correct IP address/hostname is listed within the inbound routes section of the portal.
      • Is the route being delivered to a valid route you have listed within your inbound routes, but not the primary inbound route? This indicates an issue with the primary route that is forcing us to start failing to the specified secondary inbound route and beyond.
  • Is your firewall configured to accept inbound SMTP connections from Symantec.cloud to their mail server?

Outbound email(s) not sent:

  • To look for issues, use the Email Delivery Troubleshooting Tool (under Tools > Email Delivery Troubleshooting Tool in the Symantec.cloud portal).

    • You receive "553-you are trying to use me [server-XX.tower-XXX.messagelabs.com] as a relay, but I have not been configured to let you [x.x.x.x] do this" 
      • Check the Outbound Routes section under Email Services to make sure that the correct IP Address is listed.
        • The error response should identify the IP that was sending the mail (you [x.x.x.x]).
        • The IP you are sending from if sending outbound via our services must be listed within Outbound Routes.
    • If you haven't received an error message, this indicates that the email may be queuing on your server. 
      • Perform a manual telnet on port 25 to your assigned Symantec.cloud cluster from your mail server. The appropriate cluster can be found in the Welcome Letter or based on your MX Records.

        For example, if your MX record is cluster8.eu.messagelabs.com you would telnet to cluster8out.eu.messagelabs.com

Inbound or outbound email(s) delayed:

Intermittent email failures or errors:

To look for issues, use the Email Delivery Troubleshooting Tool (under Tools > Email Delivery Troubleshooting Tool in the Symantec.cloud portal).

  • Were emails intercepted by a Symantec.cloud service such as AntiSpam or AntiMalware?
    • Use the Email Track and Trace (under Tools > Email Track and Trace) to locate information about the email. 
  • Have you or the sender received any error messages?  
    • Forward the bounce-back error message to our technical support team and provide a copy of the email for analysis of the email and headers.

 

Other email delivery issues:

  • Scenario 1: Even if a customer changes their MX Records, for domains provisioned on our service, we will use the inbound routes listed on the portal. Often, people cancel without requesting the removal of domains and we are contractually obliged to keep their configuration until the end of their paid term, or until they request removal.

    Emails sent from other Symantec customers provisioned on the same cluster will continue to be routed to the listed inbound routes and will not be delivered as per the recipient domain's current MX records unless the domain is removed or correctly canceled.

  • Scenario 2: While less likely, the issue could be that the sender has configured a static route for that recipient domain as part of Encryption Enforcement, or they have a Data Protection policy using the 'Route To' action.