550: too 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.
- Free
- Provider
- Permanent (5xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 550
- Provider
- Free (free.fr)
- Temporary or permanent
- PermanentRefused for good: the message comes back to the sender, and resending it gets the same answer.
- Who has to act
- The sender. The fix is on the sending side: your domain, your server or your list.
- What the server says
550 Too many errors from your IP
What it means
Free counts the errors each server produces in the SMTP dialogue, typically connections cut off before a message is fully transmitted. Too many of them, or behaviour that looks like a dictionary attack (sending to, or checking, long series of addresses), gets the IP blocked temporarily, for 24 hours at most. Free names the usual culprits: an open relay, the Sender Verify technique, which connects to Free to check that a sender address exists, and automatic notices such as bounces or auto-replies sent in response to spam. After a fix, a new block can still follow within 24 to 48 hours while old statistics fade.
Common causes
- Your server uses Sender Verify (callout) checks against free.fr addresses.
- Your server sends bounces or auto-replies to spam that forged free.fr senders.
- Connections to Free are often interrupted before the message is sent.
- Your server is an open relay, or tries many unknown addresses.
How to fix it
- 01Disable Sender Verify or recipient callouts toward Free.
- 02Reject spam during the SMTP session instead of accepting it and sending notices back.
- 03Check that your server is not an open relay.
- 04If you use a relay, contact its provider. Admins can write to postmaster@proxad.net with the error, the server IP and the request.
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 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.
- Too many spams from your IP.Your server sent too much spam to Free subscribers, so Free stopped accepting its connections for up to 24 hours. The page does not settle which reply code comes with it.
- 550Mailbox unavailable.The receiving server permanently refused the message for this recipient: the mailbox does not exist, cannot be reached, or the server rejected the message by policy.
550 at other providers
- 550 [SC-001]Outlook.com policy block for content or reputation.Outlook.com rejected the mail for policy reasons tied to spam-like content or to the reputation of the sending IP or domain.
- 550 [SC-002]Outlook.com block for namespace mining.Outlook.com blocked the sending IP because it behaved like a namespace miner, checking whether addresses exist without sending mail.
- 550 [SC-003]Outlook.com block for an open proxy or relay.Outlook.com rejected the mail because the sending IP appears to be an open proxy or open relay.
- 550 [SC-004]Outlook.com block after complaints.Outlook.com placed a block on the sending IP because it received complaints about mail coming from it.
- 550 [DY-001]Outlook.com refuses dynamic IP addresses.Outlook.com rejected the mail because the sending IP is dynamic address space, which it generally does not accept mail from.
- 550 [DY-002]Outlook.com block for a likely compromised sender.Outlook.com rejected the mail because the sending server or computer appears to be compromised or infected.