Articles on: Email Related

How to Handle 'Undelivered Mail Returned to Sender' Notifications from MailChannels


Our outgoing SMTP service provided by MailChannels ensures that your emails are sent securely and are checked for spam. However, there might be occasions where legitimate emails are flagged by MailChannels and are not delivered, resulting in a "bounced back" message. This guide will walk you through the steps to resolve this issue using the MailChannels Insights feature.

**Understanding the Bounce Back Message:**

When MailChannels detects an email that it suspects as spam, it will block the email from being delivered. The sender will then receive an automatic notification with the subject line "Undelivered Mail Returned to Sender." This notification serves to alert you that your message has not been sent.

**Using MailChannels Insights:**

Within the bounce back message, you will find a special link to the MailChannels Insights feature. This tool allows you to review key information about the blocked email, such as the "From" and "To" email addresses, the subject, and the date and time the email was sent.

**Taking Action with MailChannels Insights:**

Locate the bounce back email in your inbox with the subject "Undelivered Mail Returned to Sender."
Click on the provided MailChannels Insights link.
Review the details of the blocked message to ensure it was intended to be sent and is not spam.
If the email is legitimate, click the "Not Spam" button. This signals to MailChannels that the message is not spam and should not have been blocked.
Resending the Email:
After clicking "Not Spam," the MailChannels system will learn that your message is legitimate. You should now be able to resend your email without further issues.

Please Note:

The "Not Spam" feature is an important part of training the MailChannels system to recognize legitimate emails from your account.
It's crucial to only mark emails as "Not Spam" if you're certain they are legitimate, to avoid compromising the filtering system.

If you notice that this not a message that you sent, we urge you to change your email password right away.


Q: Will clicking "Not Spam" guarantee my email is delivered?
A: While it greatly increases the chances of delivery, certain factors beyond MailChannels' control may affect email delivery.

Q: How soon can I resend my email after marking it as "Not Spam"?
A: You can resend your email immediately after clicking the "Not Spam" button.

Q: What if my emails are frequently being marked as spam?
A: Review your sending practices, and ensure your emails comply with anti-spam guidelines. If the issue persists, contact support for further assistance.

We understand the importance of ensuring your emails reach their destination. By using the MailChannels Insights feature, you can help reduce false positives in spam detection and improve the deliverability of your emails.

Updated on: 11/07/2023

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