421 4.4.1: No Answer from Host
The 421 4.4.1 soft bounce means the destination mail server is not responding. Learn why connection timeouts happen and when the email will be retried.
Published · Last verified · Maintained by TamingDNS
421
4.4.1
No Answer from Host
Very Common
🔢 Enhanced Status Code Breakdown: 4.4.1
| Component | Value | Meaning |
|---|---|---|
| Class | 4 | Temporary failure (Soft bounce) |
| Subject | 4 | Network and routing |
| Detail | 1 | No Answer from Host |
Per RFC 3463 Enhanced Mail System Status Codes. Class (X) = severity, Subject (Y) = category, Detail (Z) = specific condition.
💬 What This Error Means
Your mail server knocked on the door, but nobody answered. The destination server might be offline, undergoing maintenance, or having a temporary network hiccup. Your server will keep trying to deliver it for a few days.
Common Causes
- The recipient's mail server is temporarily offline
- A firewall is blocking the connection between your server and theirs
- The other server is so busy it's not accepting new connections right now
How to Fix This
- You don't need to do anything. Your server will automatically keep trying to deliver the message
- If it still hasn't gone through after 12 hours, there might be a larger issue with the recipient's domain
- Check our Domain Checker to see if their mail servers are currently reachable
📚 Official Documentation
📋 Real-World Example Messages
These are real bounce message formats you might receive. Paste yours into the Bounce Decoder for instant analysis.
421 4.4.1 Connection timed out 421 4.4.1 [x.x.x.x] No answer from host
🔗 Related Error Codes
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