Free (free.fr) · temporary error
421: too many errors from your IP, temporary
Free has paused mail from your IP because of the errors it generated. This is the warning stage; more errors lead to the longer block.
- Free
- Provider
- Temporary (4xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 421
- Provider
- Free (free.fr)
- Temporary or permanent
- TemporaryThe sending server keeps the message and tries again later.
- Who has to act
- The sender. The fix is on the sending side: your domain, your server or your list.
- What the server says
421 Too many errors from your IP
What it means
This 421 is the warning stage before the 550 of the same name. Your IP has not reached the Free blacklist; Free has paused its mail for the moment because your server produced too many errors in the SMTP dialogue. If the errors continue, the IP is blacklisted for longer. The causes and fixes are the same as for the block itself: an open relay, Sender Verify checks against Free, or automatic notices sent in reply to spam. Fixing them now avoids the full block.
Common causes
- Sender Verify checks from your server against free.fr addresses.
- Bounces or auto-replies your server sends to forged free.fr senders.
- Interrupted or timed-out connections to Free servers.
How to fix it
- 01Turn off Sender Verify toward Free.
- 02Refuse spam during the SMTP session rather than bouncing it later.
- 03Check your server for open relay settings.
- 04If you use a relay, ask its provider to act.
Sources
What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.
- postmaster.free.fr (Free)postmaster.free.fr
Related codes
- 550Too many errors from your IP.Your server caused too many errors while talking to Free servers, or behaved like a dictionary attack, so its IP is blocked for a while.
- 421Service not available.The receiving server is closing the connection and will not take mail right now. The reply is temporary, so the sending server keeps the message and tries again later.
421 at other providers
- 421 [RP-001]Outlook.com rate limit for the sending IP.Outlook.com is limiting how fast your IP can send to it because of the IP or domain's reputation; it is temporary and your server should retry.
- 421 [RP-002]Outlook.com rate limit on this connection.Your IP has sent more over a single connection than Outlook.com allows, a limit Microsoft ties to IP and domain reputation.
- 421 [RP-003]Outlook.com connection limit.Your IP has opened more connections to Outlook.com than it is allowed, a limit Microsoft links to IP and domain reputation.
- 421Temporary error or deferral.Yahoo or AOL refused your message for now with a 421, one of its two temporary error codes. Your server should keep it and retry; repeated deferrals point to reputation or complaints.
- 421Try again later.Xfinity turned the message away for now with a generic 421. Treat it as temporary and let your server retry: Xfinity uses it for several reasons it does not spell out.
- 421Reverse DNS lookup failed.Xfinity could not complete a reverse DNS lookup for your sending IP. It treats this as temporary, so your server should retry, but a broken DNS setup keeps it failing.