421: too many recipients or mails from your Free line
Free's outgoing servers counted too many recipients or too many mails from your internet connection and stopped accepting more for now.
- 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 recipients
What it means
Like the too many connections reply, this one comes from the servers Free subscribers send through. Free has counted a large number of recipients, or of messages, coming from your line. Unless you are deliberately sending a large mailing, Free suggests the same checks as for too many connections: a mail program retrying rejected mail without end, an infected computer, or an unsecured Wi-Fi network. The block is temporary. For regular large mailings, a dedicated sending service is a better fit than a home connection.
Common causes
- A large mailing was sent through Free servers.
- A mail program resends rejected messages over and over.
- Malware on a computer on your network sends spam.
How to fix it
- 01If you sent a mailing, spread it out or move it to a sending service.
- 02Clear stuck messages from the outbox of each mail program.
- 03Scan your computers for malware and secure your Wi-Fi.
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
- 421Too many connections from your Free line.Free's outgoing mail servers refused the connection because too many were opened from your Free internet connection, at once or in a short period.
- 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.