Undeliverable or Bounce Error Messages When Sending Emails to Kayako Classic

Overview

You might get a report from end-users about getting "undeliverable" or bounce error messages (mailer-daemon) when trying to send emails to your mailbox or email queue on Kayako Classic. 

Solution

The most common cause of this issue is that the email address of the sender may have been blocked by your email server. An immediate solution that you can try is to whitelist or unblock the email address of the sender from your mail server. Your mail administrator should be able to help you in unblocking or whitelisting the email address.

Additionally, depending on the error code or message, you can take specific actions based on the recommendation such as the information found at the Mimecast SMTP Error Codes.

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Instructions for Support Agents

If a customer reports this issue, confirm the affected email address and follow the procedure below:

NOTE: Access to SendGrid is required. Check out the Kayako Access Guide for New Agents article to get access to tools.

1. Log in to SendGrid and click Suppression from the left panel.
   • NOTE: For L2 agents, use kayako_k4_pod for Kayako Classic. Kayako_k5 is for Kayako (TNK). You can get this option by switching users from the user profile on the top-left. For L1 agents, your Kayako Classic login should take you directly to the kayako_k4_pod.
     
2. Select Blocks and type the email address of the sender.
3. Click Search.
4. Review the results and share your findings with recommendations to the customer based on the Deliverability Overview article from SendGrid.

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