How to resolve false positive phishing detection by Avast antivirus?
Michael Ko
Co-founder & CEO, Suped
Published 26 Jun 2025
Updated 16 Aug 2025
7 min read
Receiving a false positive phishing detection from an antivirus program like Avast can be frustrating, especially when you know your emails are legitimate. This often occurs with business-to-business (B2B) communications, even for high-volume senders with excellent email reputation scores elsewhere. When your emails, despite having proper authentication and clean links, are flagged as phishing, it indicates an issue with the antivirus's detection algorithms, which requires direct intervention.
I've seen many cases where legitimate emails, perfectly aligned with SPF and DKIM and boasting a strict DMARC policy, still get caught in these false nets. The challenge intensifies when links within the email point to the sender's own domain and show no prior reputation issues according to various monitoring tools. This article outlines steps to troubleshoot and resolve such false positive phishing detections by Avast antivirus.
Understanding why Avast might flag legitimate emails
Antivirus programs, including Avast, use complex heuristics, signature-based detection, and real-time scanning to identify potential threats. Sometimes, legitimate email content or URLs can inadvertently trigger these detection rules, leading to a false positive. This can happen if an email contains elements that mimic known phishing patterns, even if the intent is benign.
A common trigger is the presence of links that lead to login pages or pages requiring sensitive information, even if they are on your secure domain. While Gmail and Outlook have robust mechanisms, antivirus software installed on the recipient's machine adds another layer of scrutiny. URLs that are often shortened, redirected, or associated with tracking can also sometimes raise suspicion, even if they ultimately lead to a safe, trusted destination.
The key here is that Avast maintains its own internal blacklist (or blocklist) and threat database, separate from other providers. Therefore, even if your domain and emails pass muster with Google Postmaster Tools or Microsoft's systems, you might still encounter issues with specific antivirus clients. Understanding this distinction is crucial for effective troubleshooting.
Initial troubleshooting and verification
Before contacting Avast, ensure your email infrastructure and content are beyond reproach. This involves a thorough review of your email authentication protocols and the content of the flagged emails.
Email authentication: Confirm that your Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and Domain-based Message Authentication, Reporting, and Conformance (DMARC) records are correctly configured. A strong DMARC policy, such as p=quarantine or p=reject, indicates to receiving servers that your emails are authentic. Ensure both your SPF and DKIM domains are aligned with your 'From' domain.
Link and content review: Verify that all links in your email creative use HTTPS and point directly to your legitimate sending domain. Avoid redirects if possible, as these can sometimes be misinterpreted. Check that your website is secure and free of any actual malicious content that could trigger a phishing alert. Tools like Google Safe Browsing can help with this.
Attachments: Ensure your emails do not contain unexpected attachments, which are a common vector for phishing. Even seemingly innocuous file types can sometimes trigger alerts.
Email reputation: Maintain a strong sending reputation across all major providers. While Avast operates independently, a generally healthy sending reputation can still contribute positively.
These initial steps ensure you've covered the most common reasons for email flagging. If everything appears to be in order, the issue most likely lies with Avast's specific detection algorithms.
Reporting the false positive to Avast
Once you have confirmed that your emails are legitimate and properly authenticated, the next step is to directly report the false positive to Avast. This is the most effective way to get your legitimate emails whitelisted and removed from their internal blacklist (or blocklist).
How to submit a false positive report to Avast
Use the official form: Avast provides a dedicated form for reporting false positives. You can access it directly via their False Positive File Form. Be as detailed as possible in your submission, providing context about your organization and the nature of the emails.
Email their support: In addition to the web form, it's beneficial to email Avast support directly. Common addresses include customer.support@avast.com and support@business.avast.com. Sending concurrent reports through multiple channels can sometimes expedite the review process.
Provide all necessary evidence: Include the full email header of a flagged message, a screenshot of the Avast detection (especially if it includes a unique code in the bottom left corner), and details about the sender and recipient. Clearly state that the email is a legitimate business communication and not phishing.
Sender identity: If possible, have the report submitted by someone with an official business email address from the affected domain. This can lend more credibility to your claim.
Be prepared for potential delays in response. Antivirus vendors often have large queues for false positive reviews. Persistence is key, and follow-ups can be necessary.
Advanced strategies and persistence
Dealing with false positives from antivirus companies can sometimes be a lengthy and frustrating process. Tier 1 support might initially dismiss your report or provide generic responses, insisting the detection is accurate, even for clearly legitimate content. This is a common experience, as frontline support may lack the tools or authority to thoroughly investigate complex deliverability issues.
If your initial reports are not yielding results, consider escalating the issue. This might involve politely but firmly requesting that your case be reviewed by a more senior support team or a dedicated threat analysis department. In extreme cases, a direct communication from a high-level executive at your company to Avast (or its parent company, Gen Digital, which also owns AVG) might be necessary to get traction, although this is usually a last resort.
While awaiting resolution, explore options for your recipients to whitelist your domain or email address within their Avast settings. This can provide a temporary workaround for critical communications. Also, continuously monitor your email deliverability and domain reputation using tools that check against various blocklists and reputation services. This proactive approach can help you catch potential issues before they escalate. You can also refer to a helpful list of contacts for false positive reports from various security vendors.
Final thoughts on achieving email deliverability
Resolving false positive phishing detections by Avast antivirus requires a multi-faceted approach, combining meticulous internal checks with persistent external reporting. By ensuring your email authentication is robust, your content is clean, and by directly engaging with Avast support through the appropriate channels, you significantly increase your chances of getting your legitimate emails whitelisted. While the process can test your patience, especially with antivirus vendors, diligence pays off in maintaining your email deliverability.
Remember, proactive monitoring of your domain and IP reputation, coupled with swift action on any reported issues, is fundamental to ensuring your emails consistently reach the inbox. Staying informed about how email authentication standards like DMARC, SPF, and DKIM contribute to your sending reputation can help prevent future false positives.
Views from the trenches
Best practices
Always report false positives to the antivirus vendor through their official channels, like web forms and dedicated support email addresses.
Include comprehensive evidence in your reports: full email headers, screenshots of the detection, and details about your legitimate sending practices.
Ensure your email authentication (SPF, DKIM, DMARC) is perfectly configured and aligned to strengthen your domain's credibility.
Actively monitor your domain's reputation across major email providers and blocklists to catch issues early.
Common pitfalls
Expecting an instant resolution; antivirus false positive queues can be long, and persistence is often required.
Failing to provide sufficient detail or evidence in initial reports, leading to delayed or rejected claims.
Assuming that good reputation with one provider (e.g., Google) guarantees deliverability with others, like antivirus software.
Neglecting to check your website or linked content for any underlying security issues that might trigger a detection.
Expert tips
Escalate your case if initial tier 1 support is unhelpful or dismissive; sometimes, only higher-tier or executive involvement can resolve stubborn false positives.
Consider asking high-level executives to report the issue from their business email addresses to lend more weight to the claim.
Use temporary workarounds, such as asking recipients to whitelist your domain, while awaiting a permanent resolution.
Keep a record of all communications and attempts to resolve the issue for future reference and persistence.
Marketer view
Marketer from Email Geeks says a customer sending B2B emails encountered an issue where Avast antivirus was tagging their legitimate emails as phishing, despite having a DMARC quarantine policy and proper SPF and DKIM alignment.
2023-07-01 - Email Geeks
Marketer view
Marketer from Email Geeks says all links in the creative pointed to the sender's own domain, were HTTPS, and showed no existing reputation issues when checked with common tools like Barracuda and Spam Assassin.
Avast can be frustrating, especially when you know your emails are legitimate. This often occurs with business-to-business (B2B) communications, even for high-volume senders with excellent email reputation scores elsewhere. When your emails, despite having proper authentication and clean links, are flagged as phishing, it indicates an issue with the antivirus's detection algorithms, which requires direct intervention.
