Summary
SendGrid transactional emails failing to appear in Outlook inboxes is a multifaceted problem. While a 'delivered' status confirms receipt by the mail server, it doesn't guarantee inbox placement. Key issues include a poor sender reputation (influenced by spam complaints, being blacklisted, or sending to unqualified recipients), lack of proper email authentication (SPF, DKIM, DMARC), problematic email content (spam trigger words), and low recipient engagement. Microsoft's SmartScreen filter learns from user behavior, potentially filtering consistently ignored emails. Other factors include recipient-specific local transport rules. Improving deliverability requires careful attention to sender reputation management, robust email authentication, optimized content, list hygiene, blacklist removal when necessary, and utilizing feedback loops.
Key findings
- Delivered Doesn't Equal Inbox: A 'delivered' status merely indicates the email reached the mail server; it doesn't guarantee inbox placement.
- Sender Reputation is Key: A poor sender reputation is a primary driver of deliverability issues, influenced by complaints, blacklists, and recipient quality.
- Email Authentication is Crucial: Proper implementation of SPF, DKIM, and DMARC is essential for verifying sender identity and preventing spoofing.
- Content Matters: Spam trigger words and irrelevant content contribute to emails being marked as spam.
- Engagement Impacts Deliverability: Low recipient engagement (ignoring or deleting emails) negatively impacts sender reputation.
- Local Transport Rules: In certain cases, the problem might be due to transport rules that are only related to a certain domain.
- Blacklist Status Matters: If the IP address is on a blacklist, this will reduce deliverability.
- SmartScreen Filters User Behavior: The Microsoft SmartScreen filter learns from user habits.
Key considerations
- Monitor Sender Reputation: Actively monitor sender reputation using tools provided by SendGrid and mailbox providers.
- Implement and Validate Authentication: Thoroughly implement and validate SPF, DKIM, and DMARC configurations.
- Clean and Segment Email Lists: Maintain clean email lists by removing invalid addresses and unengaged subscribers, and segment for more relevant content.
- Optimize Email Content and Send Time: Optimize email content to avoid spam triggers and ensure value for recipients.
- Investigate Local Transport Rules: If problems are isolated to a single domain, investigate and address local transport rules.
- Get Off Blocklists: Identify if you are on any email blocklists, and request to be taken off of them.
- Establish Feedback Loops: Set up and monitor feedback loops to identify recipients marking emails as spam.
- Watch Anti Spam Headers: Utilize anti spam message headers that can provide insight.
What email marketers say
10 marketer opinions
Transactional emails from SendGrid might not appear in Outlook inboxes due to a combination of factors related to sender reputation, email authentication, content, and recipient engagement. Issues like being blacklisted, poor sender score, missing authentication records (SPF, DKIM, DMARC), spam trigger words, low engagement, recipient-specific rules, and sending to unqualified prospects can cause deliverability problems. Correcting these issues and monitoring sender reputation is vital.
Key opinions
- Sender Reputation: A poor sender reputation is a primary cause of deliverability issues. Outlook and other email providers use sender reputation to determine whether to deliver emails to the inbox or spam folder.
- Email Authentication: Lack of proper email authentication (SPF, DKIM, DMARC) can lead to emails being flagged as spam. Email providers use these protocols to verify the sender's identity and prevent spoofing.
- Content Issues: Spam trigger words and irrelevant content can cause emails to be marked as spam. Content should be valuable and avoid language commonly associated with spam.
- Recipient Engagement: Low recipient engagement (ignoring or deleting emails) can negatively impact sender reputation and deliverability. Engaging content and clean email lists are crucial.
- List Hygiene: Sending emails to invalid email addresses and unqualified prospects contribute to poor deliverability and should be avoided.
Key considerations
- Monitor Sender Reputation: Regularly monitor your sender reputation using tools provided by SendGrid and other email providers. Identify and address any issues promptly.
- Implement Email Authentication: Ensure that SPF, DKIM, and DMARC are correctly configured for your domain. These protocols help verify your identity and prevent spoofing.
- Clean Email Lists: Regularly clean your email lists to remove invalid email addresses and unengaged subscribers. This improves your sender reputation and deliverability.
- Optimize Email Content: Optimize your email content to avoid spam trigger words and provide value to your subscribers. Tailor content to your audience and encourage engagement.
- Investigate Transport Rules: If the issue is limited to a single recipient domain, investigate local transport rules that might be affecting deliverability.
- Check Blacklists: Make sure you aren't on a blocklist.
Marketer view
Email marketer from Litmus explains that email deliverability problems are caused by not setting up authentication correctly. If you haven't done that you have an uphill battle with deliverability. Also to make sure you send emails people engage with, people are less likely to have issues.
24 Jun 2022 - Litmus
Marketer view
Email marketer from Mailjet explains that emails might land in spam due to various factors, including a low sender score, being blacklisted, missing authentication records (SPF, DKIM), using spam trigger words, or having a high complaint rate. They advise monitoring your sender reputation and taking steps to improve it.
10 Dec 2023 - Mailjet
What the experts say
4 expert opinions
Even if an email is reported as 'delivered,' it does not guarantee it reached the recipient's inbox. Microsoft's SmartScreen filters learn from user engagement, so consistent ignoring/deleting of emails may cause filtering to junk. Blacklist removal depends on the specific blocklist's policies. Utilizing feedback loops (FBLs) is crucial for senders to identify and remove complaining subscribers, improving overall deliverability.
Key opinions
- Delivered vs. Inbox Placement: A 'delivered' status only confirms receipt by the mail server, not delivery to the inbox.
- SmartScreen Learning: Microsoft's SmartScreen filter learns from user behavior, potentially filtering ignored emails to junk.
- Blocklist Removal Variability: Blacklist removal processes vary by blocklist, requiring identification and adherence to specific procedures.
- Feedback Loops (FBLs): FBLs notify senders of spam complaints, enabling subscriber removal and improving deliverability.
Key considerations
- Monitor Inbox Placement: Don't rely solely on 'delivered' status; monitor actual inbox placement.
- Improve User Engagement: Focus on relevant content and good list hygiene to improve user engagement and avoid SmartScreen filtering.
- Identify and Address Blacklists: Identify any blocklists you're on and follow their specific removal procedures.
- Implement Feedback Loops: Set up and utilize feedback loops to promptly address spam complaints and improve deliverability.
Expert view
Expert from Spam Resource explains that feedback loops (FBLs) are a mechanism by which mailbox providers notify senders when recipients mark their emails as spam. Participating in FBLs allows senders to identify and remove subscribers who are complaining, which can improve deliverability. They need to be set up per provider, you need to sign up to them.
16 Mar 2023 - Spam Resource
Expert view
Expert from Word to the Wise explains that Microsoft's SmartScreen filter learns from user behavior. If users consistently ignore or delete emails from a particular sender, SmartScreen may start filtering those emails into the Junk folder. He emphasizes the importance of good list hygiene and relevant content.
3 Apr 2022 - Word to the Wise
What the documentation says
5 technical articles
Email deliverability issues, especially with Outlook inboxes, can often be traced to problems with email authentication. Microsoft's anti-spam message headers provide insights into why an email was marked as spam, highlighting issues like sender IP, authentication failures, and filtering results. Implementing SPF, DKIM, and DMARC is crucial for verifying sender identity, preventing spoofing, and building trust with email providers. SPF records specify authorized mail servers, while DKIM uses digital signatures to prove message authenticity. DMARC allows domain owners to instruct receivers on handling emails that fail SPF and DKIM.
Key findings
- Anti-Spam Headers: Outlook's anti-spam message headers contain valuable information about why an email was marked as spam.
- Importance of SPF, DKIM, DMARC: SPF, DKIM, and DMARC are essential for verifying sender identity and preventing email spoofing.
- SPF Records: SPF records specify which mail servers are authorized to send emails on behalf of a domain.
- DKIM Signatures: DKIM provides a digital signature to prove that the email came from who it says it did.
- DMARC Protocol: DMARC allows domain owners to specify how email receivers should handle messages that fail SPF and DKIM checks.
Key considerations
- Analyze Anti-Spam Headers: Regularly analyze anti-spam message headers to identify and address specific deliverability issues.
- Implement SPF, DKIM, DMARC: Ensure SPF, DKIM, and DMARC are properly configured for your domain.
- Review SPF Records: Regularly review and update your SPF records to ensure they accurately reflect authorized mail servers.
- Monitor DMARC Reports: Monitor DMARC reports to identify and address potential spoofing attempts.
Technical article
Documentation from DKIM explains that DKIM protocol helps prevent email spoofing and phishing attacks by using digital signature that are encrypted. This helps prove you sent the message. This improves email deliverability and shows trust.
30 Nov 2024 - DKIM.org
Technical article
Documentation from Microsoft shares that using SPF, DKIM, and DMARC can help improve email deliverability by verifying the sender's identity and preventing spoofing. They explain how to configure these authentication methods for your domain.
30 Oct 2022 - Microsoft Learn
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