Why are SFMC emails showing as delivered but not received by the subscriber?
Matthew Whittaker
Co-founder & CTO, Suped
Published 27 May 2025
Updated 19 Aug 2025
6 min read
It's a frustrating scenario many email marketers encounter, especially when using platforms like Salesforce Marketing Cloud (SFMC): your analytics dashboard proudly declares an email as "delivered," yet the recipient adamantly states they never received it. This isn't just a minor discrepancy, it’s a critical breakdown in your communication chain that can impact everything from customer service to campaign performance. What exactly is happening when SFMC reports a successful delivery, but the email is nowhere to be found, not even in spam or promotions folders?
The core of the issue lies in the definition of "delivered." For an Email Service Provider (ESP) like SFMC, "delivered" often means the recipient's mail server has accepted the message. However, this acceptance is merely the first hurdle. After an email is accepted, it still faces an gauntlet of internal filters, security protocols, and recipient-side rules that can silently quarantine, discard, or misroute it before it ever reaches the intended inbox. This article will explore the reasons behind this perplexing problem and provide actionable steps to diagnose and resolve it.
The nuance of "delivered" in Salesforce Marketing Cloud
When Salesforce Marketing Cloud reports an email as delivered, it generally means the receiving Mail Transfer Agent (MTA) responded with a 250 OK status. This SMTP response indicates that the recipient's server has accepted responsibility for the email. From SFMC's perspective, its job is done; the message has left its systems and been handed over. It’s important to understand that this is a technical confirmation of receipt, not a guarantee of inbox placement.
The 250 OK and its implications
A 250 OK response signals that the email server acknowledged receiving your message and plans to process it. However, what happens next is entirely up to the receiving server. It may pass the email through multiple layers of spam filters, internal routing rules, or even discard it without generating a bounce message back to the sender.
The challenge here is the lack of a feedback loop for post-acceptance filtering. If an email is blocked before the 250 OK, a bounce message would typically be returned, informing you of the issue. However, once that initial acceptance occurs, the email becomes the responsibility of the recipient's server, and any subsequent filtering actions usually happen silently. This is why you see "delivered" in SFMC but no email in the inbox.
Common culprits behind unseen emails
Several factors contribute to emails disappearing after SFMC reports them as delivered. These often involve recipient-side filtering or specific configurations that prevent the email from reaching the inbox, even if it wasn't outright rejected.
One primary reason is aggressive spam filtering. While some filters reject suspicious emails outright (resulting in a bounce), others accept the email and then quarantine it, move it to a junk folder, or simply drop it without notification. This is particularly common in Business-to-Business (B2B) environments where organizations implement robust email security solutions to protect against phishing and malware. These solutions may silently discard emails deemed risky, preventing them from ever reaching the recipient's mailbox, as noted in various discussions about email status. Some sources refer to this as the mail server accepting the email, but then anti-spam filters performing additional checks, or simply not delivering it. You can review more about this issue by examining why SFMC shows email as delivered when it's not in the inbox.
Consumer ISP filtering
Spam/Promotions folders: ISPs like Yahoo and Gmail usually try to deliver mail, even if it's to a secondary folder. Check these first, and advise subscribers to do the same. An email marked delivered may still be filtered.
If issues persist with Yahoo or Gmail, consider checking their respective postmaster sites or opening a ticket if it's a widespread issue for your domain.
Corporate security measures
Advanced threat protection:Microsoft 365 and other corporate systems use sophisticated filters that scan emails for malicious content, even after initial acceptance. These emails may be quarantined or deleted without the sender receiving a bounce.
Internal policies: Some companies have strict internal policies that automatically discard emails from unknown senders or those that fail specific internal security checks, even if they pass external spam filters.
In these cases, the recipient's IT department is often the only one who can investigate and whitelist your sending domain. Emails caught in spam filters can be a common culprit.
Additionally, issues can stem from SFMC's internal processes or how subscribers are managed. SFMC's List Detective or auto-suppression lists can mark certain email addresses as undeliverable or exclude them from sends, even if they appear active in other data extensions. This means the send might be registered as successful internally for eligible recipients, but the specific individual was suppressed. You can learn more about why emails show delivered but not reaching inbox more broadly for other platforms, as the principles are similar.
Practical troubleshooting steps
When facing this problem, a systematic approach to troubleshooting is essential. Start by gathering as much detail as possible from your SFMC tracking and reports. Look beyond the simple "delivered" status. Dig into the specific SMTP replies associated with the "delivered" emails. Sometimes, even with a 250 OK, there might be additional notes or details that hint at further processing or filtering at the recipient's end.
Engage the affected subscribers directly. Ask them to thoroughly check their spam, junk, and promotions folders. Encourage them to whitelist your sending domain and email address. For B2B recipients, this might involve their IT department, as internal security measures are often the cause of silent drops. Understanding Gmail deliverability issues when using SFMC as a bulk sender could also provide insights.
Authentication Method
Status
Action
SPF
Valid
Ensure your SPF record is correctly configured to include SFMC's sending IP addresses, helping receiving servers verify your legitimacy.
DKIM
Pass
Verify DKIM signatures are properly aligned and not failing, ensuring message integrity.
DMARC
Enforced
Implement a DMARC policy to gain visibility into authentication failures and enforce policy.
Proactive measures for deliverability
Prevention is always better than cure in email deliverability. A strong sender reputation is your best defense against emails being silently dropped. This involves consistently sending high-quality, relevant content to engaged subscribers. Regularly clean your subscriber lists to remove inactive or invalid email addresses, as sending to poor-quality lists can damage your reputation and lead to more filtering.
Ensure all your emails are properly authenticated with SPF, DKIM, and DMARC. These protocols help recipient servers verify that your emails are legitimate and haven't been tampered with. Monitoring your deliverability monitoring reports, especially DMARC reports, can provide invaluable insight into authentication failures and where your emails are being filtered. You can also monitor for specific SFMC shared IP deliverability issues with Microsoft for example.
Finally, regularly check common blocklists (or blacklists) to ensure your sending IPs or domains haven't been listed. Being on a blocklist can severely impact your inbox placement, causing emails to be dropped silently or outright rejected. Understanding how email blacklists work is key to maintaining good deliverability.
Ensuring your emails reach the right destination
The "delivered but not received" paradox in Salesforce Marketing Cloud highlights the complex journey of an email after it leaves your ESP. While SFMC reporting "delivered" indicates successful handover to the recipient's server, true inbox placement depends on numerous post-acceptance factors like spam filters, corporate security solutions, and recipient-specific rules. By systematically troubleshooting, engaging with recipients, strengthening your email authentication, and proactively managing your sender reputation, you can significantly improve your chances of getting your SFMC emails into the subscriber's inbox, where they belong.
Views from the trenches
Best practices
Always inspect SFMC's detailed send logs and SMTP replies, as they provide critical clues about post-acceptance filtering by the recipient server.
Educate your subscribers on checking spam/junk folders and whitelisting your domain; this simple step resolves many delivery issues.
For B2B recipients, directly engage their IT department. Corporate firewalls often silently quarantine emails that pass initial checks.
Implement and monitor email authentication protocols (SPF, DKIM, DMARC) rigorously to build and maintain strong sender reputation.
Regularly clean your email lists to remove unengaged or invalid contacts, improving overall deliverability and reducing spam trap hits.
Common pitfalls
Misinterpreting SFMC's 'delivered' status as guaranteed inbox placement, overlooking post-acceptance filtering by recipient servers.
Neglecting to investigate SMTP replies beyond the initial '250 OK,' missing crucial details about how the email was handled.
Failing to communicate with affected subscribers about checking spam folders or whitelisting, which could resolve immediate delivery issues.
Underestimating the impact of corporate email security and firewalls, especially when sending to B2B domains, which can silently drop emails.
Ignoring sender reputation metrics and blocklist (or blacklist) status, which significantly influence whether an email reaches the inbox.
Expert tips
Monitor email metrics across various ISPs and B2B domains to identify patterns or widespread issues impacting specific receivers.
Use email deliverability testing tools to preview how your emails are scored and where they land across different mailbox providers.
Segment your audience by engagement levels and sending frequency. Highly engaged segments can often handle higher volumes and less strict filtering.
A/B test email content and subject lines to identify elements that might trigger spam filters.
Maintain an updated list of common corporate email filters and their specific requirements for optimal delivery to B2B clients.
Expert view
Expert from Email Geeks says B2B senders often discard or quarantine emails after accepting them for delivery, which is what SFMC considers 'delivered'.
2021-03-19 - Email Geeks
Expert view
Expert from Email Geeks says Yahoo is less likely to simply discard mail without bouncing it; if it happens, it's typically not by design.
Yahoo and 
Gmail usually try to deliver mail, even if it's to a secondary folder. Check these first, and advise subscribers to do the same. An email marked delivered may still be filtered.
Microsoft 365 and other corporate systems use sophisticated filters that scan emails for malicious content, even after initial acceptance. These emails may be quarantined or deleted without the sender receiving a bounce.
