SMTP Error 441: No Response from Recipient Server

Temporary failure Medium severity Network RFC 5321

What it means

SMTP Error 441 means “No Response from Recipient Server.” Your sending server could not get a response from the recipient mail server. The remote server may be down, unreachable, or the connection timed out before a response was received.

At a glance

Code441

Bounce typeSoft (temporary)

SeverityMedium

CategoryNetwork

What to doQueued and retried automatically

StandardRFC 5321

What it looks like in your mail logs

441 4.4.1 No answer from host mx.example.com; connection timed out, will retry

What does 441 mean?

SMTP code 441 indicates that the sending server attempted to connect to the recipient's mail server but received no response. This is typically a network-level or server-availability issue rather than a problem with your email content or sender reputation.

Common scenarios include the recipient mail server being temporarily offline for maintenance, network routing issues between the sending and receiving servers, or DNS problems that prevent proper server resolution. This is a transient error and your sending server should retry automatically.

How 441 plays out

Your server attempts delivery

The recipient defers with a temporary 441 reply

Your 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 441 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
441 is	✓ this code

Common causes of 441

Recipient mail server is temporarily offline or undergoing maintenance
Network routing issue between sending and receiving servers
DNS resolution failure for recipient MX records
Firewall or network appliance blocking the connection
Connection timeout due to high latency or packet loss

How to fix 441

Wait for automatic retry - most MTAs retry for 24-48 hours
Verify the recipient domain has valid MX records using MX Lookup
Check if the recipient domain is reachable from your network
If persistent, contact the recipient postmaster to report the connectivity issue

Frequently asked questions

What does SMTP error 441 mean?

SMTP error 441 means the recipient's mail server is not responding or cannot be reached. The sending server attempted to connect but received no answer within the expected time, resulting in a connection timeout. This is a temporary error typically caused by the recipient's server being offline, overloaded, or blocked by firewall rules. Your mail server will automatically retry delivery.

How do I fix SMTP 441 "No answer from host"?

First, verify the recipient's email address is correct and the domain exists by checking its MX records. Ensure your own network connection is stable and that your firewall is not blocking outbound SMTP connections on port 25. Wait 15-30 minutes and retry, as the recipient's server may be temporarily offline. If the error persists, contact the recipient's mail administrator to confirm their server is operational and accepting connections.

Is SMTP 441 a problem with my server or the recipient's server?

SMTP 441 is almost always a problem with the recipient's incoming mail server, not your outgoing server. The error indicates the recipient's server is unreachable, offline, or not responding to connection attempts. However, in rare cases, your local firewall, DNS configuration, or ISP may be blocking the connection. Verify your DNS resolution is working correctly and that outbound port 25 traffic is not being blocked.

Related bounce codes

Sources & further reading

RFC 5321 · The standard that defines this reply code RFC 3463 section 3.4 · Enhanced code X.4.1 (No answer from host), the status this maps to

Reviewed by Jennifer Jackson, Email Deliverability Analyst · June 2026 ← All bounce codes