feat: add SEND_MAIL delivery and quota controls (#986)

* feat: add SEND_MAIL delivery and quota controls

* test: cover -1 unlimited runtime for send mail quota

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix: split send limit validation and save

* refactor: move send limit counters to settings

* fix: polish send mail limit review follow-ups

* docs: note SEND_MAIL breaking change

* test: align send mail limit e2e with new messages

* fix: address review follow-ups

* fix: harden admin send mail handlers

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/views/admin/AccountSettings.vue

@@ -21,6 +21,12 @@ const { t } = useI18n({
             send_address_block_list: 'Address Block Keywords for send email',
             noLimitSendAddressList: 'No Balance Limit Send Address List',
             verified_address_list: 'Verified Address List(Can send email by cf internal api)',
+            send_mail_limit: 'Send Mail Limit',
+            send_mail_limit_tip: 'This applies to all send channels. Use -1 for unlimited and 0 to block sending.',
+            send_mail_daily_limit: 'Daily Limit',
+            send_mail_monthly_limit: 'Monthly Limit',
+            send_mail_daily_limit_invalid: 'Daily limit must be an integer greater than or equal to -1',
+            send_mail_monthly_limit_invalid: 'Monthly limit must be an integer greater than or equal to -1',
             fromBlockList: 'Block Keywords for receive email',
             block_receive_unknow_address_email: 'Block receive unknow address email',
             email_forwarding_config: 'Email Forwarding Configuration',
@@ -65,6 +71,12 @@ const { t } = useI18n({
             send_address_block_list: '发送邮件地址屏蔽关键词',
             noLimitSendAddressList: '无余额限制发送地址列表',
             verified_address_list: '已验证地址列表(可通过 cf 内部 api 发送邮件)',
+            send_mail_limit: '发信额度',
+            send_mail_limit_tip: '对全部发信渠道生效。-1 表示无限，0 表示禁止发送。',
+            send_mail_daily_limit: '每日额度',
+            send_mail_monthly_limit: '每月额度',
+            send_mail_daily_limit_invalid: '每日额度必须是大于等于 -1 的整数',
+            send_mail_monthly_limit_invalid: '每月额度必须是大于等于 -1 的整数',
             fromBlockList: '接收邮件地址屏蔽关键词',
             block_receive_unknow_address_email: '禁止接收未知地址邮件',
             email_forwarding_config: '邮件转发配置',
@@ -116,7 +128,13 @@ const ADDRESS_CREATION_SUBDOMAIN_MATCH_MODE = {
     FORCE_ENABLE: 'force_enable',
     FORCE_DISABLE: 'force_disable'
 }
+const DEFAULT_SEND_MAIL_DAILY_LIMIT = 100
+const DEFAULT_SEND_MAIL_MONTHLY_LIMIT = 3000
 const addressCreationSubdomainMatchMode = ref(ADDRESS_CREATION_SUBDOMAIN_MATCH_MODE.FOLLOW_ENV)
+const sendMailDailyLimitEnabled = ref(false)
+const sendMailMonthlyLimitEnabled = ref(false)
+const sendMailDailyLimit = ref(DEFAULT_SEND_MAIL_DAILY_LIMIT)
+const sendMailMonthlyLimit = ref(DEFAULT_SEND_MAIL_MONTHLY_LIMIT)
 const addressCreationSubdomainMatchStatus = ref({
     envConfigured: false,
     envEnabled: false,
@@ -314,6 +332,31 @@ const getSubdomainMatchPayloadValue = (mode) => {
     return null
 }
 
+const getSendMailLimitPayload = () => {
+    return {
+        dailyEnabled: sendMailDailyLimitEnabled.value,
+        monthlyEnabled: sendMailMonthlyLimitEnabled.value,
+        dailyLimit: sendMailDailyLimitEnabled.value ? sendMailDailyLimit.value : null,
+        monthlyLimit: sendMailMonthlyLimitEnabled.value ? sendMailMonthlyLimit.value : null
+    }
+}
+
+const isValidSendMailLimit = (value) => {
+    return Number.isInteger(value) && value >= -1
+}
+
+const validateSendMailLimit = () => {
+    if (sendMailDailyLimitEnabled.value && !isValidSendMailLimit(sendMailDailyLimit.value)) {
+        message.error(t('send_mail_daily_limit_invalid'))
+        return false
+    }
+    if (sendMailMonthlyLimitEnabled.value && !isValidSendMailLimit(sendMailMonthlyLimit.value)) {
+        message.error(t('send_mail_monthly_limit_invalid'))
+        return false
+    }
+    return true
+}
+
 const fetchData = async ({ suppressErrorMessage = false } = {}) => {
     try {
         const res = await api.fetch(`/admin/account_settings`)
@@ -337,6 +380,15 @@ const fetchData = async ({ suppressErrorMessage = false } = {}) => {
         addressCreationSubdomainMatchMode.value = getSubdomainMatchModeByStoredValue(
             addressCreationSubdomainMatchStatus.value.storedEnabled
         )
+        const sendMailLimitConfig = res.sendMailLimitConfig
+        sendMailDailyLimitEnabled.value = !!sendMailLimitConfig?.dailyEnabled
+        sendMailMonthlyLimitEnabled.value = !!sendMailLimitConfig?.monthlyEnabled
+        sendMailDailyLimit.value = sendMailDailyLimitEnabled.value
+            ? sendMailLimitConfig.dailyLimit
+            : DEFAULT_SEND_MAIL_DAILY_LIMIT
+        sendMailMonthlyLimit.value = sendMailMonthlyLimitEnabled.value
+            ? sendMailLimitConfig.monthlyLimit
+            : DEFAULT_SEND_MAIL_MONTHLY_LIMIT
     } catch (error) {
         if (!suppressErrorMessage) {
             message.error(error.message || "error");
@@ -346,6 +398,9 @@ const fetchData = async ({ suppressErrorMessage = false } = {}) => {
 }
 
 const save = async () => {
+    if (!validateSendMailLimit()) {
+        return
+    }
     try {
         const payload = {
             blockList: addressBlockList.value || [],
@@ -356,7 +411,8 @@ const save = async () => {
             emailRuleSettings: emailRuleSettings.value,
             addressCreationSettings: {
                 enableSubdomainMatch: getSubdomainMatchPayloadValue(addressCreationSubdomainMatchMode.value)
-            }
+            },
+            sendMailLimitConfig: getSendMailLimitPayload()
         }
         await api.fetch(`/admin/account_settings`, {
             method: 'POST',
@@ -437,6 +493,35 @@ onMounted(async () => {
                     </template>
                 </n-select>
             </n-form-item-row>
+            <n-form-item-row :label="t('send_mail_limit')">
+                <n-flex vertical style="width: 100%;">
+                    <n-flex justify="space-between" align="center">
+                        <n-text>{{ t('send_mail_daily_limit') }}</n-text>
+                        <n-flex align="center">
+                            <n-switch v-model:value="sendMailDailyLimitEnabled" :round="false" />
+                            <n-input-number
+                                v-model:value="sendMailDailyLimit"
+                                :disabled="!sendMailDailyLimitEnabled"
+                                :min="-1"
+                            />
+                        </n-flex>
+                    </n-flex>
+                    <n-flex justify="space-between" align="center">
+                        <n-text>{{ t('send_mail_monthly_limit') }}</n-text>
+                        <n-flex align="center">
+                            <n-switch v-model:value="sendMailMonthlyLimitEnabled" :round="false" />
+                            <n-input-number
+                                v-model:value="sendMailMonthlyLimit"
+                                :disabled="!sendMailMonthlyLimitEnabled"
+                                :min="-1"
+                            />
+                        </n-flex>
+                    </n-flex>
+                    <n-text depth="3">
+                        {{ t('send_mail_limit_tip') }}
+                    </n-text>
+                </n-flex>
+            </n-form-item-row>
             <n-form-item-row :label="t('fromBlockList')">
                 <n-select v-model:value="fromBlockList" filterable multiple tag :placeholder="t('fromBlockList')">
                     <template #empty>