SMTP
Simuler une réponse 551 User Not Local
The recipient is not local to this server and the server does not accept mail for forwarding. Unlike 251, this is a rejection — the server will not relay the message.
Voir la référence complète →1 Réponse HTTP
HTTP/1.1 551 User Not Local
Content-Type: application/json
Date: Tue, 25 Feb 2026 12:00:00 GMT
Content-Length: 54
{
"error": "server_error",
"message": "User Not Local"
}
2 Tester avec curl
curl -i https://httpbin.org/status/551
3 Retourner 551 User Not Local dans votre framework
django
from django.http import JsonResponse
def my_view(request):
return JsonResponse(
{"error": "server_error", "message": "User Not Local"},
status=551,
)
flask
from flask import Flask, jsonify
app = Flask(__name__)
@app.route("/endpoint")
def my_endpoint():
return jsonify({"error": "server_error", "message": "User Not Local"}), 551
fastapi
from fastapi import FastAPI
from fastapi.responses import JSONResponse
app = FastAPI()
@app.get("/endpoint")
def my_endpoint():
return JSONResponse(
content={"error": "server_error", "message": "User Not Local"},
status_code=551,
)
express.js
// Express.js
app.get('/endpoint', (req, res) => {
res.status(551).json({"error": "server_error", "message": "User Not Local"});
});
spring boot
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.util.Map;
@RestController
public class MyController {
@GetMapping("/endpoint")
public ResponseEntity<Map<String, Object>> myEndpoint() {
return ResponseEntity
.status(551)
.body(Map.of("error", "user_not_local",
"message", "User Not Local"));
}
}
go net/http
package main
import (
"encoding/json"
"net/http"
)
func myHandler(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(551)
json.NewEncoder(w).Encode(map[string]string{
"error": "user_not_local",
"message": "User Not Local",
})
}
ruby on rails
class MyController < ApplicationController
def my_action
render json: {"error": "server_error", "message": "User Not Local"},
status: :user_not_local
end
end
asp.net core
// ASP.NET Core Minimal API
app.MapGet("/endpoint", () =>
Results.Json(
new { error = "user_not_local", message = "User Not Local" },
statusCode: 551
)
);