What can I do if users aren't receiving email verification emails due to company spam filters?

Key findings

• Corporate filters: Corporate, educational, governmental, and banking domains often employ very strict spam filters, leading to non-delivery or quarantine of verification emails.
• DMARC policy: A DMARC policy set to p=reject can cause emails to be outright blocked if authentication isn't perfectly aligned. Ensure your authentication is properly configured.
• HTML and headers: While messy HTML from drag-and-drop editors is common, unusual or non-standard From headers can trigger filters.
• Delivery logs: Email service provider (ESP) delivery logs may show an email as 'delivered' even if it's subsequently blocked or quarantined by the recipient's internal server.
• Transactional emails: Verification and invitation emails are a type of transactional email. They are critical, but still face deliverability challenges, similar to other transactional emails going to spam.

Key considerations

• Authentication review: Regularly check your DMARC, SPF, and DKIM records to ensure they are correctly set up and aligned, especially if you use a p=reject policy.
• Standardize 'From' header: Ensure your email 'From' header is as standard and vanilla as possible to avoid triggering filters that look for unusual formatting.
• User education: Provide clear on-screen instructions for users to check their spam or junk folders, as many are familiar with this process due to two-factor authentication.
• Recipient IT engagement: When possible, encourage affected users (especially paying customers) to contact their corporate IT department to investigate why emails are being blocked and request whitelisting.
• Alternative verification: Consider offering alternative verification methods, such as SMS, although this may not verify the email address itself.

Key opinions

• User expectation: Users are increasingly accustomed to receiving verification codes or links for two-factor authentication, making it easier to instruct them to check their spam folders.
• Corporate domain struggle: Emails sent to corporate domains are particularly prone to being blocked, even when delivery logs indicate they were successfully sent. This is a common pain point for troubleshooting email deliverability issues.
• Whitelisting effectiveness: When IT departments whitelist a sender, emails typically go through, confirming that recipient-side filters are the cause of blocking. Learn how to get your emails whitelisted.
• Double opt-in goal: Marketers aim for double opt-in to ensure subscriber quality, but deliverability issues with verification emails directly impede this goal.
• Microsoft commonality: Many observed issues with emails being quarantined or not received are linked to recipients using Microsoft email services.

Key considerations

• User experience: Prioritize a smooth user experience by making on-screen instructions explicit about checking spam folders and providing clear next steps if the email is delayed.
• Customer service integration: Equip your customer support team with knowledge and tools (like access to delivery logs) to assist users who aren't receiving verification emails.
• Segment audience: Recognize that different recipient types (e.g., free users vs. corporate clients) may require different approaches to support and troubleshooting.
• Product team collaboration: Work with product teams to explore alternative verification methods (e.g., phone number) or even prompts for users to add a secondary, personal email address, especially for B2C services that might also be used at work.
• Proactive monitoring: Monitor your deliverability rates and engage with your ESP's support to understand the nuances of why emails are not reaching specific domains or inboxes. An Auth0 community thread discusses this.

Key opinions

• DMARC rigor: Using a DMARC policy of p=reject is an aggressive approach that requires meticulous authentication setup, as any failure will result in emails being blocked.
• Header sensitivity: Even if technically valid, 'From' headers that appear 'funky' or non-vanilla can lead to email filtering issues, particularly with strict corporate filters. This is part of the reasons why emails fail.
• Microsoft's strictness: Microsoft has become increasingly strict about RFC compliance for email address syntax, leading to rejections for non-compliant mail, an important factor for improving deliverability with Microsoft.
• Educational domain challenges: K12 and higher education institutions often have unique and highly restrictive mail policies, sometimes only allowing mail from pre-designated domains, making deliverability a particular nightmare for university domains.
• Internal filters: Some corporate filters are so aggressive they discard mail even after it's been accepted by the recipient's Mail Exchange (MX) server, leading to situations where emails appear delivered but are unseen by the user.
• Sender score: Dips in sender score can indicate issues affecting deliverability, even if other authentication aspects are clean.

Key considerations

• Audit sender setup: Routinely review your email authentication records (DMARC, SPF, DKIM) to ensure they are squeaky-clean and robust, especially with strict DMARC policies.
• Content and syntax: Beyond technical authentication, assess email content for anything that might appear 'phishy' or trigger spam filters. Ensure proper RFC compliance for headers and email syntax. You can refer to advice on avoiding RFC rule breaks.
• Leverage ESPs: Work closely with your Email Service Provider's support team, as they often have more detailed logs and tools to diagnose deliverability issues at a granular level.
• Direct communication: If emails are persistently blocked by specific corporate or educational domains, direct communication with their IT departments (via your affected users) may be necessary to understand the blocking reasons.
• Alternative addresses: Be prepared that for highly restrictive domains (like some K12 schools), the only viable solution might be to request users provide a non-work email address.

Key findings

• RFC compliance: Adherence to Request for Comments (RFC) standards for email formatting and headers is increasingly critical, with major providers enforcing these rules more strictly. See how RFC 5322 relates to real-world email.
• Authentication standards: SPF, DKIM, and DMARC are essential for verifying sender legitimacy and are foundational for improving inbox placement, helping to boost email deliverability rates.
• Sender reputation: A consistent positive sender reputation (e.g., as reflected in Sender Score or Google Postmaster Tools) directly correlates with successful deliverability.
• Consent requirements: Regulations like the CAN-SPAM Act underscore the importance of explicit opt-in for email messages, which directly impacts how filters perceive your mail.
• Bounce analysis: Understanding different bounce types and their causes is crucial for diagnosing and resolving underlying deliverability problems.

Key considerations

• Implement robust authentication: Ensure your domain has correctly configured SPF, DKIM, and DMARC records to authenticate your emails and reduce the likelihood of them being flagged as spam.
• Monitor deliverability metrics: Continuously monitor your sender reputation and deliverability rates through available tools to detect issues promptly and take corrective action.
• Optimize content: Design email content that is clean, clear, and avoids common spam triggers, including suspicious links or overly promotional language in transactional messages.
• Educate recipients: Guide users on how to check their spam or junk folders and, if necessary, how to add your sending address to their safe sender list to prevent future blocking.
• Address website activity: Ensure your website is active and associated with your sending domain, as sending from inactive or blank sites can raise suspicion with ISPs. The FTC provides consumer advice on how to get less spam.