E-mail notifications report as delivered but individuals don't appear to receive message

Problem

The notification report card and logs show 100% successful email delivery but some users do not see the corresponding email in their inbox.

Environment

• All versions of xMatters

• Corporate email solutions with security implementations checking for spam and malicious messages

Resolution

xMatters marks an email as delivered when it has been successfully handed off to the downstream email provider or mail gateway. This means xMatters has no further control over what happens to the email inside your organization's mail environment.

To investigate and resolve cases where users do not see emails even though they are marked as delivered:

• Confirm delivery in xMatters

  • Review the event log or notification report in xMatters to verify that the email device for the affected user shows as Delivered.

  • If email responses are expected, you can also confirm acknowledgements in the logs.

• Check for suppression / complaints list entries

  • In some cases, an address can be added to a suppression or complaints list.

  • This can prevent further delivery even if the sender address is on the user's safe/permit list.

• Verify the user's email configuration

  • Check that the email address in the user's xMatters profile is correct and up to date.

  • Send a test or validation email to the user from xMatters, and also send a regular email from outside xMatters to confirm the address is working.

  • If problems persist for a specific user, recreate the email device in xMatters.

• Review internal mail security and filtering

  • Ask your mail administrators to check whether messages from xMatters are being quarantined, classified as spam, or blocked after acceptance by the mail gateway.

  • Verify that your email security solution is not treating bursts of xMatters traffic as a denial-of-service (DoS) attack.

Email domain filtering

Corporate email systems often employ DoS sensing and other protections when they see large volumes of incoming messages. To reduce the likelihood of false positives, consider explicitly allowing the xMatters email domains in your mail and security systems.

xMatters email address domains:
mg.mx.xmatters.com

IP address filtering

xMatters does not recommend filtering the IP addresses and ranges associated with your xMatters service, for the reasons explained here.

Cause

The corporate email security system or downstream email infrastructure is preventing messages from reaching user inboxes after xMatters has successfully handed them off.