4.4.1
Enhanced Status Code 4.4.1: No Answer from Host
Temporary failure
Medium severity
Network
RFC 3463
What it means
Enhanced Status Code 4.4.1 means “No Answer from Host.” The receiving mail server is not responding to connection attempts. The server may be down, unreachable due to network issues, or a firewall may be blocking the connection. Your MTA will retry automatically.
At a glance
Code4.4.1
Bounce typeSoft (temporary)
SeverityMedium
CategoryNetwork
What to doQueued and retried automatically
StandardRFC 3463
Jun 10 14:37:09 mail postfix/smtp[15220]: 3B71C2403A: to=<rcpt@example.com>, relay=none, delay=300, status=deferred (connect to mx.example.com[192.0.2.25]:25: Connection timed out)What does 4.4.1 mean?
Enhanced status code 4.4.1 means your sending server could not establish a connection with the recipient mail server. The server did not respond to the TCP connection attempt on port 25. This is typically a network-level or server availability issue.
Common causes include the recipient server being temporarily offline, DNS resolution issues where MX records point to an unreachable IP, or network routing problems between your server and the destination. This is usually a temporary condition.
How 4.4.1 plays out
Your server attempts delivery
The recipient defers with a temporary
4.4.1 replyYour server queues the message and retries on a back-off schedule
It delivers on a later attempt, or becomes a hard bounce if it keeps failing
Where 4.4.1 sits: soft vs hard bounce
| Soft bounce (4xx) | Hard bounce (5xx) | |
|---|---|---|
| Nature | Temporary | Permanent |
| SMTP class | 4xx | 5xx |
| What to do | Let it retry | Suppress the address |
| Recoverable? | Often | No |
| 4.4.1 is | ✓ this code |
Common causes of 4.4.1
- Recipient mail server is temporarily offline
- Network routing issue between sending and receiving servers
- MX records point to an unreachable IP address
- Firewall blocking inbound port 25 on the recipient server
- DNS resolution delay or failure for MX records
How to fix 4.4.1
- Allow automatic retries - most resolve within hours
- Verify recipient domain MX records using MX Lookup
- Check if the issue is specific to one recipient domain or widespread
- Contact recipient postmaster if unresponsive for 24+ hours
Frequently asked questions
What does bounce code 4.4.1 "No answer from host" mean?
Bounce code 4.4.1 means the sending mail server attempted to connect to the recipient's server but received no response; the connection timed out. This is a temporary error indicating the recipient's mail server is unreachable, possibly due to being offline, experiencing network issues, or being blocked by a firewall. Your sending server will automatically retry delivery over the next several days.
How do I fix a 4.4.1 connection timeout error?
First, verify the recipient's email address and domain are correct. Check that your DNS is resolving the recipient's MX records properly. Ensure your firewall is not blocking outbound connections on SMTP port 25. If the problem affects all outgoing mail, check your server's network connectivity and DNS configuration. If it only affects one domain, the issue is likely on the recipient's end; wait and retry, as the problem is often temporary.
Is 4.4.1 a problem with my email server?
Usually not. The 4.4.1 error most often indicates the recipient's server is unreachable or not responding. However, it can occasionally be caused by your own network issues, DNS misconfiguration, or firewall rules blocking outbound SMTP traffic. To determine the cause, try sending to a different domain; if other domains work fine, the problem is on the recipient's side. If all outgoing mail fails, investigate your own server's network connectivity, DNS settings, and firewall rules for port 25 access.
Related bounce codes
Sources & further reading
Reviewed by Jennifer Jackson, Email Deliverability Analyst · June 2026
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