Troubleshooting Undelivered Emails with Successful (R/D) Logs.

When the recipient's server acknowledges the receipt of emails, the email log file will display the statuses R (Received) and D (Delivered) in the mail event section.

These statuses confirm that the emails are being successfully triggered from Salesforce. However, if the emails are not reaching the recipient’s mailbox, it is likely due to filtering by the recipient’s server, often caused by their security policies.

To address this, provide the Message ID of the mail event marked as D (Delivered) in the email log file to the recipient's IT team. They can use this information to investigate why their server is blocking or filtering the email.

Additionally, ensure that SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) are properly set up for your email-sending domain. These protocols enhance your email-sending reputation and reduce the likelihood of such issues.

If SPF and DKIM is setup correctly, please make sure these settings are in place in your org.