Error: 553-Message filtered for legitimate email incorrectly blocked as spam

Products

• Email Security.cloud

Issue/Introduction

Email Security.cloud detects legitimate inbound or outbound emails as spam (False Positive) when they trigger specific signaturing or heuristic engines. This includes detections by Skeptic Heuristics, Cynic, or blocks related to outbound scanning.

Symptoms

• Error: 553 - Message Filtered
• Track and Trace shows action as Quarantined, Blocked, or Subject Tagged.
• Detection method identified as Heuristic or Signaturing.
• Detections persist even after whitelisting the sender.

Environment

Email Security.cloud

Cause

The Anti-Spam service identifies patterns in the email body, attachments, or sender reputation that match spam criteria.

Resolution

Submit false positive samples for analysis to amend detection rules:

Step 1: Retrieve an email sample

1. Obtain the original email in message/rfc822 format (.eml or .msg).
2. If the email is larger than 5 MB, upload it as a password-protected ZIP file directly to the support case. Provide the password in a separate case note.
3. If the file is smaller than 5 MB, proceed to the submission portal.

Step 2: Submit an email sample for analysis

1. Log in to the Email Security.cloud portal.
2. Select Tools > Email Submissions.
3. Click Submit False Positive.
4. Select the sample file and click Check.
5. If the result is This email is currently classified as spam, enter the contact details and click Submit Sample.
6. Record the Submission ID and Sample ID from the confirmation email (from [email protected]).

Additional Information

To speak with a customer representative or a Support Engineer, see Contact Support. Scroll to the bottom of the page and click on the respective region.

Additional Information

• Check the status of spam false positive submissions for Email Security.cloud
• Submitting spam samples for emails flagged with error code 553 - Message Filtered