diff --git a/email_ui.py b/email_ui.py
index 25dea63..9e8c491 100644
--- a/email_ui.py
+++ b/email_ui.py
@@ -1,20 +1,23 @@
 # -*- coding: utf-8 -*-
 """
-email_ui.py  —  一键群发工具 (独立可跑版)
---------------------------------------------------
+email_ui.py  —  一键群发工具 (强化校验版)
+--------------------------------------
 运行:  python email_ui.py
 """
-import os, logging, random
+import os, logging, re, random
 from datetime import datetime
 import gradio as gr
-from send_email_module import send_email   # 同目录导入
+from send_email_module import send_email
 
-EMAIL_CONFIG_KEY = "default"          # 对应 config/default.json
+EMAIL_CONFIG_KEY = "default"           # 对应 config/default.json
 LOG_FILE = "email_send_log.txt"
-logging.basicConfig(level=logging.INFO, format="%(asctime)s  %(levelname)s  %(message)s")
+logging.basicConfig(level=logging.INFO,
+                    format="%(asctime)s  %(levelname)s  %(message)s")
+
+EMAIL_RE = re.compile(r"^[^@\s]+@[^@\s]+\.[^@\s]+$")   # 简易邮箱正则
 
 
-# -------------------- 内部函数 --------------------
+# -------------------- 工具 --------------------
 def _load_template(file_obj):
     if file_obj is None:
         return ""
@@ -22,30 +25,55 @@ def _load_template(file_obj):
         return f.read()
 
 
+def _error(msg):
+    """生成统一的红字提示 + 让 state 为空 -> Send 仍锁定"""
+    return gr.update(value=f"<p style='color:red'>❌ {msg}</p>"), None
+
+
+# -------------------- 预览 --------------------
 def preview_email(to_addrs, subject, html_file, language,
                   want_receipt, want_read_receipt):
+    # 0. 模板存在
     tpl = _load_template(html_file)
     if not tpl:
-        return gr.HTML.update("<p style='color:red'>❌ 请先上传 HTML 模板</p>"), None
+        return _error("请先上传 HTML 模板")
 
+    # 1. 收件人非空且格式合法
+    raw_addrs = [a.strip() for a in to_addrs.split(",") if a.strip()]
+    if not raw_addrs:
+        return _error("收件人邮箱不能为空")
+    if invalid := [a for a in raw_addrs if not EMAIL_RE.match(a)]:
+        return _error(f"邮箱格式非法: {', '.join(invalid)}")
+
+    # 2. 主题非空
+    if not subject.strip():
+        return _error("主题不能为空")
+
+    # 3. 模板至少包含 {{recipient_name}}
+    if "{{recipient_name}}" not in tpl:
+        return _error("模板缺少 {{recipient_name}} 占位符")
+
+    # ---- 全部通过，生成预览 ----
     preview = (tpl.replace("{{recipient_name}}", "there")
-                  .replace("{{recipient_email}}", "example@example.com")
-                  .replace("{{encoded_recipient_email}}", "ENCODED_EXAMPLE")
-                  .replace("{{timestamp}}", datetime.now().isoformat()))
+                 .replace("{{recipient_email}}", "example@example.com")
+                 .replace("{{encoded_recipient_email}}", "ENCODED_EXAMPLE")
+                 .replace("{{timestamp}}", datetime.now().isoformat()))
+
     state = {
-        "addresses": [a.strip() for a in to_addrs.split(",") if a.strip()],
-        "subject": subject,
+        "addresses": raw_addrs,
+        "subject": subject.strip(),
         "template": tpl,
         "language": language,
         "want_receipt": want_receipt,
         "want_read_receipt": want_read_receipt,
     }
-    return gr.update(value=preview), state     # ✅ 任何版本通用
+    return gr.update(value=preview), state
 
 
+# -------------------- 发送 --------------------
 def send_emails(state):
     if not state:
-        return "⚠️ 请先 Preview。"
+        return "⚠️ 请先 Preview 成功后再发送。"
     out_lines = []
     for addr in state["addresses"]:
         res = send_email(
@@ -59,32 +87,35 @@ def send_emails(state):
         out_lines.append(line)
         with open(LOG_FILE, "a", encoding="utf-8") as f:
             f.write(line + "\n")
-    return "\n".join(out_lines)
+    return "<br>".join(out_lines).replace("\n", "<br>")
 
 
 # -------------------- Gradio UI --------------------
-with gr.Blocks(css=".gr-button {min-width:6rem}") as demo:
+with gr.Blocks(css=".gr-button {min-width:8rem}") as demo:
     gr.Markdown("## ✉️ 简易 EDM 群发工具")
 
     addrs = gr.Textbox(label="收件人（逗号分隔）", placeholder="foo@bar.com, alice@x.com")
     subj  = gr.Textbox(label="主题", placeholder="Subject here")
     tpl   = gr.File(label="上传 HTML 模板")
-    lang  = gr.Radio(["english", "chinese"], value="english", label="语言")
+    lang  = gr.Radio(["english", "chinese"], value="chinese", label="语言")
     with gr.Row():
         rcpt    = gr.Checkbox(label="投递回执")
         read_r  = gr.Checkbox(label="已读回执")
 
     preview_btn = gr.Button("Preview ⬇️")
-    send_btn    = gr.Button("Send ✈️", interactive=False)
+    send_btn    = gr.Button("Send (确认发送) ✈️", interactive=False)
     out_html    = gr.HTML()
     state_box   = gr.State()
 
-    preview_btn.click(preview_email, [addrs, subj, tpl, lang, rcpt, read_r],
-                      [out_html, state_box]) \
-               .then(lambda s: gr.update(interactive=s is not None),
-                     inputs=state_box, outputs=send_btn)
+    preview_btn.click(
+        preview_email,
+        [addrs, subj, tpl, lang, rcpt, read_r],
+        [out_html, state_box]
+    ).then(
+        lambda s: gr.update(interactive=s is not None),
+        inputs=state_box, outputs=send_btn
+    )
     send_btn.click(send_emails, state_box, out_html)
 
 if __name__ == "__main__":
-    demo.queue().launch(server_port=7880, show_api=False)  # ← 关闭 API 元数据
-
+    demo.queue().launch(server_port=7880, show_api=False)