Why am I getting Sanesecurity errors in Outlook?

Key findings

• Error indication: The error code (e.g., Sanesecurity.Jurlbl.fa85bd) specifically points to an issue with a URL in your email content, not necessarily the sender's IP or domain reputation directly.
• URL blocklist: Sanesecurity utilizes various data feeds, including Jurlbl, which is a blocklist of URLs associated with spam, phishing, or malware. If a URL in your email is listed, it can trigger these errors.
• Outlook's filtering: Outlook (and other email providers) often integrate with or use data from various anti-spam and antivirus services, including Sanesecurity's feeds, to filter incoming messages. For more on how Outlook filters, see why Microsoft Outlook blocks emails.
• Potential false positives: While blocklists are effective, sometimes legitimate URLs can be mistakenly listed (a false positive). This often requires investigation and a delisting request to the blocklist operator.

Key considerations

• Identify the problematic URL: The hexadecimal suffix in the error message (e.g., fa85bd) might correspond to a specific URL that caused the listing. You need to identify which link is triggering the filter.
• Check URL reputation: Verify the reputation of all URLs in your email. If your dedicated link tracking domain is new or has been used for questionable purposes by others, it might be the culprit. Consider using a tool to check URL reputation.
• Review email content: Even if the URL itself is not malicious, the context in which it appears or other elements of the email (e.g., suspicious keywords, excessive links, poor formatting) might contribute to the spam score. This is a common reason for emails landing in spam folders.
• Contact Sanesecurity appropriately: Do not send delisting requests or email headers to their malware sample submission address. Sanesecurity provides specific contact points for false positives.

Key opinions

• Initial confusion: Many marketers initially feel these errors are false positives, especially for typical promotional emails.
• Content analysis: Marketers frequently review their email content, noting if it contains multiple links or no attachments, trying to pinpoint the issue.
• Link tracking impact: Changing link tracking to a dedicated domain is a common first step, but it often doesn't resolve the issue if the new domain's reputation is also problematic or if other content issues exist.
• Specific error parsing: The specific error message, like "Sanesecurity.Jurlbl.fa85bd", quickly leads marketers to suspect a URL problem within their email.

Key considerations

• Beyond false positives: While a false positive is possible, it's crucial to thoroughly investigate whether a URL in the email is indeed associated with malicious activity, even inadvertently. You can learn more about why emails go to spam.
• URL reputation is key: Marketers must understand that the reputation of every link in their email, including tracking links, heavily influences deliverability. A dedicated tracking domain helps, but its own reputation must be maintained.
• Bounce message analysis: Carefully analyzing the complete bounce message can provide clues about the specific issue. For Outlook-specific issues, check URIports' guide on Outlook error 550.
• Engagement and content quality: Focus on sending engaging, relevant content to avoid spam complaints and improve overall sender reputation. Spam filters assess various factors, not just blocklists, to decide inbox placement.

Key opinions

• Error interpretation: Experts advise that the error "Sanesecurity.Jurlbl.fa85bd" clearly points to a URL issue, and the hex suffix helps identify the specific URL that triggered the block.
• False positive vs. negative: It's crucial to correctly identify if the issue is a false positive (legitimate content blocked) versus a false negative (problematic content allowed). The Sanesecurity error is typically a false positive if your URL is clean.
• Jurlbl function: Jurlbl (Junk URL Blocklist) is designed to list URLs of bad content, meaning email headers are generally not helpful for their delisting process, only the URL itself.
• Legitimate listings: A URL listing (like mmtrkr.com) might be a perfectly reasonable blocklist entry if the domain is indeed associated with suspicious activity.
• Volunteer effort: Sanesecurity is often run by volunteers, which can affect their response times and how delisting requests are handled. Delisting should be approached respectfully.

Key considerations

• Proper communication channels: Do not send delisting requests to email addresses designated for malware samples. Always use the specified false positive reporting mechanisms on the blocklist's website. This applies to any email blocklist (also called blacklist), for more see what an email blacklist is.
• SMTP response details: Always capture and provide the complete SMTP response when seeking help with delivery errors, as it contains vital diagnostic information. More general Outlook deliverability issues are discussed in this article on Outlook deliverability.
• Understand listing reasons: Investigate why a URL might be listed, even if you believe it's clean. Could it be a compromised domain, a past association with spam, or even a very generic, overused tracking domain? Further information is available in InMotion Hosting's guide on 550 spam messages.
• Proactive reputation management: Maintain a strong sender and domain reputation to minimize the chances of being caught by such filters. This includes proper email authentication (SPF, DKIM, DMARC), consistent sending volume, and low complaint rates.

Key findings

• Multi-layered filtering: Modern email filtering systems use multiple layers, including reputation checks (IP, domain), content analysis, and third-party blocklist lookups, to determine inbox placement.
• URL blocklist effectiveness: URL-based blocklists, such as Sanesecurity's Jurlbl, are highly effective at stopping emails containing known malicious or spammy links, even if the sender's reputation is otherwise good.
• Content scanning: Email messages are scanned for suspicious URLs, not just the sender's domain. This means embedded tracking links or links to external resources can trigger blocklists.
• False positive mechanisms: Reputable blocklist providers (also called blacklist providers) typically offer clear procedures for reporting and requesting review of false positives. Understanding how email blocklists work is crucial.

Key considerations

• URL shorteners: Using generic URL shorteners can be risky, as the underlying domains might be widely used by spammers and are thus frequently blocklisted.
• Dedicated domains: Employing dedicated domains for link tracking and content hosting is a best practice, but maintaining their reputation is paramount. This includes implementing DMARC for email authentication (learn more in our guide to DMARC, SPF, and DKIM).
• Proactive monitoring: Regularly monitor your domain and IP addresses across major email blocklists. Early detection allows for quicker resolution and prevents long-term reputation damage.
• Content best practices: Beyond authentication, adhering to email content best practices, such as clear subject lines, relevant content, and avoiding spammy language or excessive links, significantly improves deliverability. Spotler's blog on junk emails in Microsoft Outlook provides more detail.