feat: hide send mail UI when not configured (#827)

- Add isSendMailEnabled and isAnySendMailEnabled functions in common.ts
- Return enableSendMail field in /open_api/settings
- Hide sendmail tab, sendbox tab, and reply button when send mail is not configured
- Check RESEND_TOKEN, SMTP_CONFIG, and SEND_MAIL binding per domain

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/store/index.js

@@ -34,6 +34,7 @@ export const useGlobalState = createGlobalState(
             cfTurnstileSiteKey: '',
             enableWebhook: false,
             isS3Enabled: false,
+            enableSendMail: false,
             showGithub: true,
             disableAdminPasswordCheck: false,
             enableAddressPassword: false,

frontend/src/views/Index.vue

@@ -156,15 +156,15 @@ onMounted(() => {
               </n-button>
             </n-input-group>
           </div>
-          <MailBox :key="mailBoxKey" :showEMailTo="false" :showReply="true" :showSaveS3="openSettings.isS3Enabled"
+          <MailBox :key="mailBoxKey" :showEMailTo="false" :showReply="openSettings.enableSendMail" :showSaveS3="openSettings.isS3Enabled"
             :saveToS3="saveToS3" :enableUserDeleteEmail="openSettings.enableUserDeleteEmail"
             :fetchMailData="fetchMailData" :deleteMail="deleteMail" :showFilterInput="true" />
         </n-tab-pane>
-        <n-tab-pane name="sendbox" :tab="t('sendbox')">
+        <n-tab-pane v-if="openSettings.enableSendMail" name="sendbox" :tab="t('sendbox')">
           <SendBox :fetchMailData="fetchSenboxData" :enableUserDeleteEmail="openSettings.enableUserDeleteEmail"
             :deleteMail="deleteSenboxMail" />
         </n-tab-pane>
-        <n-tab-pane name="sendmail" :tab="t('sendmail')">
+        <n-tab-pane v-if="openSettings.enableSendMail" name="sendmail" :tab="t('sendmail')">
           <SendMail />
         </n-tab-pane>
         <n-tab-pane name="accountSettings" :tab="t('accountSettings')">

worker/src/commom_api.ts

@@ -3,6 +3,7 @@ import { Hono } from 'hono'
 import utils from './utils';
 import { CONSTANTS } from './constants';
 import { isS3Enabled } from './mails_api/s3_attachment';
+import { isAnySendMailEnabled } from './common';
 
 const api = new Hono<HonoCustomType>
 
@@ -38,6 +39,7 @@ api.get('/open_api/settings', async (c) => {
         "cfTurnstileSiteKey": c.env.CF_TURNSTILE_SITE_KEY,
         "enableWebhook": utils.getBooleanValue(c.env.ENABLE_WEBHOOK),
         "isS3Enabled": isS3Enabled(c),
+        "enableSendMail": isAnySendMailEnabled(c),
         "version": CONSTANTS.VERSION,
         "showGithub": !utils.getBooleanValue(c.env.DISABLE_SHOW_GITHUB),
         "disableAdminPasswordCheck": utils.getBooleanValue(c.env.DISABLE_ADMIN_PASSWORD_CHECK),

worker/src/common.ts

@@ -1,7 +1,8 @@
 import { Context } from 'hono';
 import { Jwt } from 'hono/utils/jwt'
+import { WorkerMailerOptions } from 'worker-mailer';
 
-import { getBooleanValue, getDomains, getStringValue, getIntValue, getUserRoles, getDefaultDomains, getJsonSetting, getAnotherWorkerList, hashPassword } from './utils';
+import { getBooleanValue, getDomains, getStringValue, getIntValue, getUserRoles, getDefaultDomains, getJsonSetting, getAnotherWorkerList, hashPassword, getJsonObjectValue } from './utils';
 import { unbindTelegramByAddress } from './telegram_api/common';
 import { CONSTANTS } from './constants';
 import { AdminWebhookSettings, WebhookMail, WebhookSettings } from './models';
@@ -9,6 +10,37 @@ import i18n from './i18n';
 
 const DEFAULT_NAME_REGEX = /[^a-z0-9]/g;
 
+/**
+ * Check if send mail is enabled for a specific domain
+ */
+export const isSendMailEnabled = (
+    c: Context<HonoCustomType>,
+    mailDomain: string
+): boolean => {
+    // Check resend token for domain or global
+    const resendEnabled = c.env.RESEND_TOKEN || c.env[
+        `RESEND_TOKEN_${mailDomain.replace(/\./g, "_").toUpperCase()}`
+    ];
+    if (resendEnabled) return true;
+
+    // Check SMTP config for domain
+    const smtpConfigMap = getJsonObjectValue<Record<string, WorkerMailerOptions>>(c.env.SMTP_CONFIG);
+    if (smtpConfigMap && smtpConfigMap[mailDomain]) return true;
+
+    // Check SEND_MAIL binding
+    if (c.env.SEND_MAIL) return true;
+
+    return false;
+}
+
+/**
+ * Check if send mail is enabled for any configured domain
+ */
+export const isAnySendMailEnabled = (c: Context<HonoCustomType>): boolean => {
+    const domains = getDomains(c);
+    return domains.some(domain => isSendMailEnabled(c, domain));
+}
+
 export const generateRandomName = (c: Context<HonoCustomType>): string => {
     // name min length min 1
     const minLength = Math.max(