Laposte.net 451 4.7.1 LPN007_512: spam suspicion.

Laposte temporarily blocked the IP because of suspected spam behavior.

How to fix 451 4.7.1 LPN007_512.

Retrying or final
Retrying
A 4xx reply. Your server keeps the message queued and tries again.
Who is at fault
Sender
Your authentication, reputation, content, or sending pace.
Severity
WarningSpam Suspicion
Temporary451 4.7.1 LPN007_512

This code signals elevated complaint rates, traps, or content Laposte finds risky. Without adjustments it can escalate to permanent blocks.

Next steps

  1. 1Reduce sending speed and prioritise highly engaged French subscribers.
  2. 2Remove addresses that hard bounced or never opened in the past six months.
  3. 3Verify that no compromised accounts are injecting mail into your system.
  4. 4Monitor Signal Spam and other FBL feeds for indicators of abuse.
Laposte.net documentationEvery raw SMTP 451 reply

More Laposte.net codes.

Full Laposte.net playbook

Other Laposte.net fixes

450 4.7.1 LPN027_503Service refusedRetrying
550 5.7.1 LPN007_517DMARC policy rejectFinal
450 4.1.8 LPN007_405Invalid senderRetrying
450 4.1.7 LPN007_411MX misconfigurationRetrying
450 4.2.1Mailbox inactiveRetrying
450 4.7.0 LPN007_510Service refusedRetrying

In the glossary

Bounce (Soft)A soft bounce is when an email fails to deliver for a temporary reason, like a full inbox or a short outage at the recipient mail server. The address is still valid, and the email may be delivered if you try again later.
DeferralA deferral is when a receiving email server temporarily refuses a message but suggests trying again later.
ThrottlingThrottling is when inbox providers or your email platform slow or limit how many emails you can send in a set time. It acts like a speed limit so big sends do not overwhelm their systems or hurt your reputation.
GreylistingGreylisting is an anti-spam technique where a receiving server temporarily rejects emails from unknown senders to test if they are legitimate.

What Laposte.net expects from senders →

More references.

SMTP field manual.

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