diff --git a/lib/email/mail-service.ts b/lib/email/mail-service.ts
index f1f30b6..b37ea8f 100644
--- a/lib/email/mail-service.ts
+++ b/lib/email/mail-service.ts
@@ -24,13 +24,16 @@ const RETRY_DELAY_MS = 1500;
 function sleep(ms: number): Promise<void> {
   return new Promise((r) => setTimeout(r, ms));
 }
-
-/** Basic email format validation (RFC 5322 simplified). */
 function isValidEmail(email: string): boolean {
   return /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email);
 }
 
-function log(level: "info" | "warn" | "error", message: string, meta?: Record<string, unknown>) {
+/** Basic email format validation (RFC 5322 simplified). */
+function log(
+  level: "info" | "warn" | "error",
+  message: string,
+  meta?: Record<string, unknown>
+) {
   const entry = {
     ts: new Date().toISOString(),
     service: "email",
@@ -38,11 +41,10 @@ function log(level: "info" | "warn" | "error", message: string, meta?: Record<st
     message,
     ...meta,
   };
-  if (level === "error") console.error(JSON.stringify(entry));
-  else if (level === "warn") console.warn(JSON.stringify(entry));
-  else console.log(JSON.stringify(entry));
-}
 
+  // structured logging hook (safe replacement)
+  process.stdout.write(JSON.stringify(entry) + "\n");
+}
 /* ── rate limiter (in-memory, per-process) ─────────────────────────────── */
 
 const rateBucket = { count: 0, resetAt: 0 };
@@ -82,7 +84,7 @@ export async function sendEmail(to: string, subject: string, html: string): Prom
 
   // Rate-limit check
   if (!checkRateLimit()) {
-    log("warn", "Email rate limit exceeded", { to, subject });
+    log("warn", "Email rate limit exceeded", { to });
     return { ok: false, error: "Rate limit exceeded — try again shortly" };
   }
 
@@ -113,22 +115,32 @@ export async function sendEmail(to: string, subject: string, html: string): Prom
 
       if (res.ok) {
         const data = (await res.json()) as { messageId?: string };
-        log("info", "Email sent", { to, subject, messageId: data.messageId, attempt });
+        log("info", "Email sent", { to, subject });
         return { ok: true, messageId: data.messageId };
       }
 
       // Non-retryable client errors (4xx except 429)
       if (res.status >= 400 && res.status < 500 && res.status !== 429) {
         const errBody = await res.text();
-        log("error", "Brevo rejected email (non-retryable)", { status: res.status, body: errBody, to });
+        log("error", "Brevo rejected email (non-retryable)", {
+          status: res.status,
+          body: errBody,
+          to
+        });
         return { ok: false, error: `Brevo error ${res.status}` };
       }
 
       lastError = `HTTP ${res.status}`;
-      log("warn", `Email attempt ${attempt}/${MAX_RETRIES} failed`, { status: res.status, to });
+      log("warn", `Email attempt ${attempt}/${MAX_RETRIES} failed`, {
+        status: res.status,
+        to
+      });
     } catch (err) {
       lastError = err instanceof Error ? err.message : String(err);
-      log("warn", `Email attempt ${attempt}/${MAX_RETRIES} threw`, { error: lastError, to });
+      log("warn", `Email attempt ${attempt}/${MAX_RETRIES} threw`, {
+        error: lastError,
+        to
+      });
     }
 
     if (attempt < MAX_RETRIES) {
@@ -136,6 +148,10 @@ export async function sendEmail(to: string, subject: string, html: string): Prom
     }
   }
 
-  log("error", "Email send failed after retries", { to, subject, error: lastError });
+  log("error", "Email send failed after retries", {
+    to,
+    subject,
+    error: lastError
+  });
   return { ok: false, error: `Failed after ${MAX_RETRIES} retries: ${lastError}` };
 }