Why are Braze emails showing as delivered but not appearing in the user's inbox?
Matthew Whittaker
Co-founder & CTO, Suped
Published 4 Jul 2025
Updated 19 Aug 2025
8 min read
It can be incredibly frustrating when Braze shows an email as delivered yet the recipient insists it never landed in their inbox. This is a common point of confusion for email marketers and deliverability professionals. The discrepancy often lies in the definition of delivered and the complex journey an email takes after leaving your sending platform. Let's explore the various reasons why this might happen and how to investigate the issue.
The true meaning of 'delivered'
When Braze reports an email as delivered, it means the email was successfully accepted by the recipient's mail server. This is confirmed by a 250 OK response from the receiving server. Crucially, this acceptance does not guarantee that the email will then appear in the user's primary inbox, spam folder, or any accessible folder at all. It simply means the mail server took possession of the email. After this point, the receiving server's internal filters and policies take over, determining the email's ultimate fate.
This distinction is vital for understanding deliverability. Your ESP (Email Service Provider), in this case Braze, confirms its part of the transaction is complete: the email left their system and was handed off successfully. What happens next is entirely up to the recipient's mail server. This is why you often see emails reported as delivered by various ESPs, including SFMC, Marketo, or Mailchimp, but still fail to reach the user.
Understanding what delivered truly means is the first step in troubleshooting. It shifts your focus from your ESP's sending capabilities to the receiving end's processing. The Message Activity Log in Braze provides valuable insights, but often stops short once the message is accepted by the initial mail server.
Common reasons emails go missing
So, if Braze says it's delivered, where could the email be? The most common culprits are client-side sorting and server-side filtering. Users might have inadvertently moved the email or set up rules that automatically redirect messages. On the server side, even after initial acceptance, powerful anti-spam filters continue to analyze the email. This can lead to the email being placed in a spam or junk folder, or even quarantined, without a bounce message being sent back to Braze.
For corporate email accounts, quarantine folders are a frequent destination for seemingly delivered but missing emails. These are often managed by IT departments and might require the user to check a separate quarantine portal or receive a digest email to release messages. For personal accounts, especially Gmail users, emails might end up in the Promotions or Social tabs, or directly in the spam folder, without the user immediately noticing. It's important to differentiate between an email being filtered to spam and being silently dropped entirely, as discussed in why emails go missing.
User-level blocking or filtering is also a possibility. A recipient might have mistakenly (or intentionally) marked your email as spam in the past, or set up a personal rule to move certain senders to a specific folder. While Braze's user lookup tool can confirm general eligibility for a campaign, it won't necessarily reveal these granular, user-specific inbox behaviors. This is particularly relevant for Office 365 environments where end-users often have control over their own rules and blocklists (or block lists).
Braze's 'delivered' status
Definition: Email accepted by the recipient's mail server with a 250 OK response.
ESP perspective: Indicates the email successfully left Braze's infrastructure.
Visibility: Tracking limited once the receiving server accepts the message.
Actual inbox placement
Definition: Email is visible in the user's primary inbox or other accessible folders (spam, junk).
User experience: What the recipient actually sees and can interact with.
Influencing factors: Sender reputation, content, authentication, user preferences, and internal mailbox provider rules.
Sometimes, the issue is more nuanced, involving the recipient's mail service performing additional checks after accepting the email. This is especially true for Microsoft and Outlookinboxes, where emails might be silently dropped or diverted to hidden folders without user notification. These hidden diversions or silent drops are often due to low sender reputation or authentication failures.
Reputation, authentication, and content filtering
Sender reputation is paramount. If your domain or IP address has a poor reputation, even if emails are technically delivered to the receiving server, they may be heavily filtered. Factors like high complaint rates, low engagement, sending to spam traps, or appearing on a blocklist (or blacklist) can severely impact your inbox placement. Monitoring your blocklist status is crucial.
Email authentication protocols like SPF, DKIM, and DMARC play a critical role. While Braze handles much of this, ensuring your DNS records are correctly configured and aligned is essential. If any of these authentication checks fail, mail servers are more likely to filter your emails or even reject them entirely, even if Braze's logs indicate initial acceptance. You can learn more about this in our guide to DMARC, SPF, and DKIM.
Content is another major factor. Emails with excessive spammy keywords, broken links, or suspicious formatting can trigger filters. Mailbox providers analyze the entire email, from headers to body content, to determine its legitimacy. A sudden change in email volume or content can also raise red flags, especially if your domain reputation isn't robust. This is a common reason why some emails are sent to spam, as detailed in why your emails go to spam.
Ultimately, the mailbox provider has the final say on where an email lands. For example, Outlook.com has specific filtering algorithms that might affect emails even if they pass initial delivery checks. There is no single universal reason why an email gets filtered, making it challenging to diagnose without direct insight from the recipient's mail server.
Troubleshooting and user-side actions
When facing this issue, the first step is to engage the recipient. Ask them to thoroughly check their spam, junk, promotions, and any other filtered folders. They should also check if they have any personal rules set up that might be diverting your emails. If it's a corporate email, advise them to contact their IT department to check quarantine logs.
Encourage the user to add your sending domain to their address book or whitelist their email client. If the email is found in spam, asking them to move it to the inbox is an important positive signal to the mailbox provider, as it indicates a false positive. Continuously monitoring your DMARC reports can also provide insights into authentication failures that might lead to messages being blocked (or blacklisted).
For ongoing issues, consider using an email deliverability test to simulate sending to various inboxes and identify potential filtering points. While Braze can confirm acceptance by the receiving server, a comprehensive deliverability platform can often show you where emails land within different mailbox providers, providing a clearer picture of your actual inbox placement.
Final thoughts
When Braze indicates an email is 'delivered' but it doesn't appear in the recipient's inbox, the problem lies beyond the initial handoff to the mail server. It typically points to post-delivery filtering by the recipient's mail service or user-side configurations. Addressing these issues requires a multi-faceted approach, focusing on improving sender reputation, ensuring proper authentication, optimizing content, and guiding users to check their filtered folders. Consistent monitoring and a proactive approach to deliverability are key to ensuring your Braze emails not only get delivered but also land where your users expect them.
Views from the trenches
Best practices
Maintain a healthy sender reputation by monitoring engagement and avoiding spam traps.
Ensure all email authentication protocols (SPF, DKIM, DMARC) are correctly configured and aligned.
Segment your audience and personalize content to increase engagement and reduce complaint rates.
Regularly clean your email lists to remove inactive or invalid addresses.
Common pitfalls
Assuming 'delivered' means 'in inbox' without further investigation.
Ignoring low engagement metrics, which can negatively impact sender reputation.
Failing to educate users on checking spam or promotions folders for missing emails.
Not configuring custom sending domains, which can impact branding and deliverability.
Expert tips
Use a deliverability platform to get granular insights into inbox placement across various providers.
Set up DMARC monitoring to receive reports on authentication failures and potential abuse.
Regularly review your email content for potential spam triggers or formatting issues.
Engage directly with recipients to confirm where (or if) emails are being received.
Marketer view
Marketer from Email Geeks says that emails might be landing in a quarantine folder, especially for corporate mail systems, which users may need to access separately.
2023-11-15 - Email Geeks
Marketer view
Marketer from Email Geeks notes that Braze's definition of 'delivered' often means the email was accepted by the receiving server, suggesting the user should check filters, spam folders, or additional anti-abuse systems if a 250 OK response was received.
Braze shows an email as delivered yet the recipient insists it never landed in their inbox. This is a common point of confusion for email marketers and deliverability professionals. The discrepancy often lies in the definition of delivered and the complex journey an email takes after leaving your sending platform. Let's explore the various reasons why this might happen and how to investigate the issue.
Gmail users, emails might end up in the Promotions or Social tabs, or directly in the spam folder, without the user immediately noticing. It's important to differentiate between an email being filtered to spam and being silently dropped entirely, as discussed in why emails go missing.
Outlookinboxes, where emails might be silently dropped or diverted to hidden folders without user notification. These hidden diversions or silent drops are often due to low sender reputation or authentication failures.
