Learn how to fix the “Sendmail fatal No recipient addresses found in message header “ error. Our Sendmail Support team is here to help you with your questions and concerns.

Sendmail fatal No recipient addresses found in message header

If you have been running into the following error, it lets us know that the Sendmail mail transfer agent has had a problem while processing an email message.

Sendmail fatal no recipient addresses found in message header

This error occurs because the SMTA could not find any recipient addresses in the message header.

Without question, recipient addresses are key for Sendmail to know where to deliver the email.

Our experts have put together these tips to help you fix this error:

• To begin with, we have to examine the header of the email message that caused the error. We have to make sure that the “To:” or “Cc:” fields contain valid recipient email addresses. In some cases, the error may be due to a malformed message header or missing information.
• Then, make sure that the email message follows the standard email format. The header should include fields like “From:”, “To:”, “Subject:”, etc. We have to make sure that the recipient addresses are properly formatted and separated by commas if there are multiple recipients.
• Next, we have to review the Sendmail configuration files to make sure that there are no misconfigurations that may be behind the issue. So, we have to look for any unusual settings or modifications that might interfere with the handling of recipient addresses.
• In case an error occurs during the sending process, we have to check the script or application responsible for sending emails. Hence, we have to check we are correctly specifying recipient addresses and generating valid message headers.
• At this point, we have to check the Sendmail log files for more information about the error. We have to look for entries related to the specific error and gather additional details.
• Finally, our experts recommend sending a simple test email with valid recipient addresses to see if the issue persists. This will help us find out if the problem is specific to certain emails or if it’s a more general problem.

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Conclusion

At the end of the day, our Support Experts demonstrated how to fix the “ Sendmail fatal No recipient addresses found in message header” error.