Blocked Emails
Emails rejected by receiving servers due to IP reputation, blacklisting, or policy restrictions.
What are Blocked Emails?
Blocked emails are messages actively rejected by a receiving server due to reputation issues, policy violations, or security concerns. Unlike bounces, which reflect delivery attempts that failed after reaching the destination server, blocked emails are stopped before they even get in.
Why it matters
Blocks indicate a systemic problem with your sending practices. If left unresolved, they can escalate to domain or IP blacklisting, making it nearly impossible to reach inboxes. They’re often more serious than bounces because they suggest your entire sending infrastructure has been flagged.
How it works
When you send an email, the receiving server evaluates your IP, domain, and content. If it detects problems—like sending from an untrusted IP, using spammy content, or lacking proper authentication—it can block the message outright. AutoSend tracks these blocks so you can investigate and take corrective action.
Examples
A new IP sending 50,000 emails on day one without Email Warmup.
Content flagged by spam filters (e.g., “FREE MONEY!!!”).
Your domain appearing on a major blocklist.
Best practices
Warm up new IPs gradually.
Authenticate your domain with SPF, DKIM, and DMARC.
Regularly check public blocklists and delist if necessary.
Monitor engagement—low opens and high spam complaints increase the risk of blocks.
Related terms
Email Deliverability, Suppression List, Reported Spam
FAQs
How do I know if my emails are being blocked?
Your ESP will log block errors returned by receiving servers. You may also see sudden drops in deliverability or engagement across a specific provider like Gmail or Outlook.
How do I recover from being blocked?
First, identify the reason—too many complaints, no authentication, sudden volume spikes. Then fix the issue, request delisting from blocklists, and warm up your sending reputation again.
Are blocks permanent?
No, but they can last as long as the issue persists. Once corrected, most providers will begin accepting your emails again.
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