What if an email says delivered but the recipient has not received it?
Learn the steps to take when an email is delivered, but the recipient does not receive it.
Why does this happen
When an email is sent, it is marked as Delivered once the recipient server accepts it with a 250 OK response. However, the server can then direct the email to the inbox, queue it for later, route it to the spam folder, or even discard it.
This is done by major inbox providers (e.g., Gmail, Yahoo, Outlook), as well as by IT departments and individual users who set up firewalls or filtering rules.As a result, even though most legitimate emails should land in the intended inboxes, your message might end up in the spam/junk folder or, in rare cases, be deleted.
Inbox Providers do not share any information on how the messages are later filtered. Humanic is only notified about the initial acceptance and marks the email as Delivered. Any subsequent events (e.g., open/click events, unsubscribes) require recipient engagement.
How to avoid this?
If you are in contact with the user
The easiest way to solve this is by cooperating with the end user. If you have direct communication with the recipient, you can ask them to check these places for your email:
Corporate spam filters or firewalls
Personal inbox filtering
Promotional, spam, or deleted folders
Group inboxes or queues
If they find it, ask them to mark the email as Not Spam or add your domain to an allowlist.
If you are not in contact with the user
Debugging without direct contact with the user is challenging. However, there are some optimizations that can improve your chances of delivering to their inbox next time:
Configure DMARC to build trust with the inbox provider
Warm up new domains slowly before sending large volumes
Change all links in your email to use your own domain (matching your sender domain)
Turn off open and click tracking
Reduce the number of images in your email
Improve wording to be succinct, clear, and avoid spammy words
We have an extensive but practical deliverability guide that covers these topics in more detail.
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