diff --git a/src/pages/ProjectDetail.tsx b/src/pages/ProjectDetail.tsx
index 6e33db8..22a9233 100644
--- a/src/pages/ProjectDetail.tsx
+++ b/src/pages/ProjectDetail.tsx
@@ -540,6 +540,23 @@ function MailTab({ projectId }: { projectId: string }) {
   );
 }
 
+// "Name <a@b>" 또는 "a@b" → 표시용 짧은 이름(이름 또는 @앞)
+function addrName(a: string): string {
+  a = a.trim();
+  const m = a.match(/^"?([^"<]+?)"?\s*<[^>]*>$/);
+  if (m) return m[1].trim();
+  const at = a.indexOf("@");
+  return at > 0 ? a.slice(0, at) : a;
+}
+// 수신자(받는사람+참조)가 많으면 "둘 + 외 N명"으로 줄이고, 전체는 title(hover)로.
+function recipientSummary(to: string, cc: string) {
+  const parts = `${to},${cc}`.split(",").map((s) => s.trim()).filter(Boolean);
+  const names = parts.map(addrName);
+  const full = parts.join(", ");
+  const short = names.length <= 2 ? names.join(", ") : `${names.slice(0, 2).join(", ")} 외 ${names.length - 2}명`;
+  return { short: short || "—", full: full || "—" };
+}
+
 function MailRow({ projectId, mail, nameOf }: { projectId: string; mail: ProjectMail; nameOf: (e?: string | null) => string }) {
   const qc = useQueryClient();
   const [open, setOpen] = useState(false);
@@ -549,52 +566,56 @@ function MailRow({ projectId, mail, nameOf }: { projectId: string; mail: Project
   const save = useMutation({ mutationFn: () => putMailNote(projectId, mail.messageId, memo), onSuccess: invalidate });
   const hide = useMutation({ mutationFn: () => hideMail(projectId, mail.messageId, !mail.hidden), onSuccess: invalidate });
   const when = mail.ts ? formatDateTime(new Date(mail.ts).toISOString()) : mail.date;
+  const rcpt = recipientSummary(mail.to, mail.cc);
 
   return (
     <Card className={classNames("overflow-hidden", mail.hidden && "opacity-60")}>
-      <div className="flex items-start gap-1 px-2 sm:px-3 py-3">
-        <button onClick={() => setOpen((o) => !o)} className="mt-0.5 text-ink-muted shrink-0 p-1 rounded hover:bg-canvas">
-          {open ? <ChevronDown size={16} /> : <ChevronRight size={16} />}
-        </button>
-        <button onClick={() => setOpen((o) => !o)} className="min-w-0 flex-1 text-left">
-          <span className="flex items-center gap-2">
-            <span className="text-sm font-semibold text-ink truncate">{mail.subject || "(제목 없음)"}</span>
-            {mail.note && <span className="text-[10px] bg-chip-bg text-navy rounded-pill px-1.5 py-0.5 shrink-0">메모</span>}
-            {mail.hidden && <span className="text-[10px] bg-divider text-ink-muted rounded-pill px-1.5 py-0.5 shrink-0">숨김</span>}
-          </span>
-          <span className="block text-xs text-ink-muted truncate mt-0.5">{mail.from}</span>
-          <span className="block text-sm text-ink-secondary truncate mt-1">{mail.snippet}</span>
-          {/* 메일 리스트에 메모도 함께 표시 */}
-          {mail.note && (
-            <span className="mt-2 block text-xs text-ink bg-navy-subtle/40 border border-navy-subtle rounded-control px-2.5 py-1.5 line-clamp-2">
-              📝 {mail.note}
-            </span>
-          )}
-        </button>
-        <div className="flex items-center gap-1 shrink-0">
-          <span className="text-[11px] text-ink-muted tabular hidden sm:block">{when}</span>
-          <button onClick={() => hide.mutate()} title={mail.hidden ? "다시 보이기" : "숨기기"}
-            className="p-1.5 rounded text-ink-muted hover:text-ink hover:bg-canvas">
-            {mail.hidden ? <Eye size={15} /> : <EyeOff size={15} />}
+      <div className="flex flex-col sm:flex-row sm:items-stretch">
+        {/* 메일 본문 요약 (제목·보낸이→받는이·스니펫) */}
+        <div className="flex items-start gap-1 min-w-0 flex-1 px-2 sm:px-3 py-3">
+          <button onClick={() => setOpen((o) => !o)} className="mt-0.5 text-ink-muted shrink-0 p-1 rounded hover:bg-canvas">
+            {open ? <ChevronDown size={16} /> : <ChevronRight size={16} />}
           </button>
+          <button onClick={() => setOpen((o) => !o)} className="min-w-0 flex-1 text-left">
+            <span className="flex items-center gap-2">
+              <span className="text-sm font-semibold text-ink truncate">{mail.subject || "(제목 없음)"}</span>
+              {mail.hidden && <span className="text-[10px] bg-divider text-ink-muted rounded-pill px-1.5 py-0.5 shrink-0">숨김</span>}
+            </span>
+            <span className="block text-xs text-ink-muted truncate mt-0.5">
+              {addrName(mail.from)} <span className="text-ink-muted/70">→</span>{" "}
+              <span title={rcpt.full} className="cursor-help underline decoration-dotted decoration-ink-muted/40 underline-offset-2">{rcpt.short}</span>
+            </span>
+            <span className="block text-sm text-ink-secondary truncate mt-1">{mail.snippet}</span>
+          </button>
+          <div className="flex items-center gap-1 shrink-0">
+            <span className="text-[11px] text-ink-muted tabular hidden md:block">{when}</span>
+            <button onClick={() => hide.mutate()} title={mail.hidden ? "다시 보이기" : "숨기기"}
+              className="p-1.5 rounded text-ink-muted hover:text-ink hover:bg-canvas">
+              {mail.hidden ? <Eye size={15} /> : <EyeOff size={15} />}
+            </button>
+          </div>
+        </div>
+        {/* 메모 열 — 클릭 전에도 항상 보이고 바로 요약을 적을 수 있다 */}
+        <div className="sm:w-72 shrink-0 border-t sm:border-t-0 sm:border-l border-divider px-3 py-2 flex flex-col bg-canvas/30">
+          <textarea
+            value={memo}
+            onChange={(e) => setMemo(e.target.value)}
+            onBlur={() => { if (memo !== (mail.note ?? "")) save.mutate(); }}
+            placeholder="요약 메모 입력…"
+            rows={2}
+            className="w-full text-xs leading-snug text-ink bg-transparent rounded-control px-2 py-1.5 resize-none border border-transparent hover:border-border focus:border-navy focus:bg-surface focus:outline-none min-h-[44px]"
+          />
+          {mail.noteEditedBy && <span className="text-[10px] text-ink-muted mt-1 px-2 truncate">✎ {nameOf(mail.noteEditedBy)}</span>}
         </div>
       </div>
       {open && (
-        <div className="px-4 pb-4 pt-1 border-t border-divider space-y-3">
+        <div className="px-4 pb-4 pt-2 border-t border-divider">
           <div className="text-xs text-ink-muted grid grid-cols-1 sm:grid-cols-2 gap-x-6 gap-y-1">
-            <div><span className="text-ink-secondary font-medium">보낸사람</span> {mail.from}</div>
-            <div><span className="text-ink-secondary font-medium">받는사람</span> {mail.to}</div>
+            <div className="sm:col-span-2"><span className="text-ink-secondary font-medium">보낸사람</span> {mail.from}</div>
+            <div className="sm:col-span-2"><span className="text-ink-secondary font-medium">받는사람</span> {mail.to || "—"}</div>
             {mail.cc && <div className="sm:col-span-2"><span className="text-ink-secondary font-medium">참조</span> {mail.cc}</div>}
-            <div className="sm:col-span-2 sm:hidden"><span className="text-ink-secondary font-medium">시각</span> {when}</div>
-          </div>
-          <div>
-            <div className="flex items-center justify-between mb-1">
-              <span className="form-label !mb-0">공동 메모 <span className="text-ink-muted font-normal">· 프로젝트 구성원 누구나 수정</span></span>
-              {mail.noteEditedBy && <span className="text-[11px] text-ink-muted">마지막 수정 {nameOf(mail.noteEditedBy)}</span>}
-            </div>
-            <Textarea value={memo} onChange={(e) => setMemo(e.target.value)}
-              onBlur={() => { if (memo !== (mail.note ?? "")) save.mutate(); }}
-              placeholder="이 메일에 대한 팀 메모를 남기세요. (대응 방향·할 일·합의 내용 등)" style={{ minHeight: 80 }} />
+            <div><span className="text-ink-secondary font-medium">시각</span> {when}</div>
+            <div><span className="text-ink-secondary font-medium">발견 메일함</span> {nameOf(mail.mailbox)}</div>
           </div>
         </div>
       )}