docs: clarify domain fallback behavior

CHANGELOG.md

@@ -17,7 +17,7 @@
 
 - fix: |Admin| 管理员重置邮箱地址密码时改为前端 SHA-256 后提交，后端只接受并存储哈希值，避免该接口继续接收明文密码
 - fix: |Address| 管理员邮箱地址列表与用户绑定地址列表不再返回已存储的地址密码哈希值，避免列表接口暴露敏感字段
-- fix: |Address| 统一规范化配置域名、收件地址域名与前缀的空白和大小写，覆盖 `DOMAINS`、`DEFAULT_DOMAINS`、`USER_ROLES.domains`、随机子域名、转发规则、SMTP 与 `SEND_MAIL` 域名匹配，避免大小写配置或入站收件域名导致创建、收件、转发或发信失败（issue #926）
+- fix: |Address| 统一规范化配置域名、收件地址域名与前缀的空白和大小写，覆盖 `DOMAINS`、`DEFAULT_DOMAINS`、`USER_ROLES.domains`、随机子域名、转发规则、SMTP 与 `SEND_MAIL` 域名匹配，并明确空 `DEFAULT_DOMAINS` / 角色域名回退到 `DOMAINS` 的行为，避免大小写配置或入站收件域名导致创建、收件、转发或发信失败（issue #926）
 - fix: |AI 提取| 将 AI 邮件识别默认 Workers AI 模型切换为支持 JSON Mode 且未弃用的 `@cf/meta/llama-3.1-8b-instruct-fast`，并在文档中补充 `@cf/zai-org/glm-4.7-flash` 结构化输出兼容性提示（issue #1029）
 - fix: |CI| 将 GitHub Actions 与 e2e Docker 镜像统一升级到 Node.js 24，适配 Wrangler 4.90.0 的运行时要求
 - fix: |Frontend| 修复 iOS Safari 点击输入框时因移动端表单控件字号过小导致页面自动放大的问题

CHANGELOG_EN.md

@@ -17,7 +17,7 @@
 
 - fix: |Admin| Hash address passwords in the frontend before admin reset requests, and make the backend accept and store only the hash instead of plaintext
 - fix: |Address| Stop returning stored address password hashes from the admin address list and user bound-address list APIs to avoid exposing sensitive fields
-- fix: |Address| Normalize whitespace and casing for configured domains, inbound recipient domains, and prefixes across `DOMAINS`, `DEFAULT_DOMAINS`, `USER_ROLES.domains`, random subdomains, forwarding rules, SMTP, and `SEND_MAIL` domain matching to avoid create, receive, forward, or send failures caused by mixed-case configuration or inbound recipient domains (issue #926)
+- fix: |Address| Normalize whitespace and casing for configured domains, inbound recipient domains, and prefixes across `DOMAINS`, `DEFAULT_DOMAINS`, `USER_ROLES.domains`, random subdomains, forwarding rules, SMTP, and `SEND_MAIL` domain matching, and clarify that empty `DEFAULT_DOMAINS` / role domains fall back to `DOMAINS`, to avoid create, receive, forward, or send failures caused by mixed-case configuration or inbound recipient domains (issue #926)
 - fix: |AI Extract| Switch the default Workers AI model for AI email recognition to the JSON Mode-compatible, non-deprecated `@cf/meta/llama-3.1-8b-instruct-fast`, and document structured-output compatibility guidance for `@cf/zai-org/glm-4.7-flash` (issue #1029)
 - fix: |CI| Upgrade GitHub Actions and e2e Docker images to Node.js 24 to satisfy Wrangler 4.90.0 runtime requirements
 - fix: |Frontend| Prevent iOS Safari from auto-zooming the page when focusing mobile form controls with small font sizes

vitepress-docs/docs/en/guide/worker-vars.md

@@ -48,6 +48,8 @@
 | `SEND_MAIL_DOMAINS`                   | JSON      | Restrict which sender domains can use the `SEND_MAIL` binding; when unset or empty, all domains are allowed                                                                                                     | `["example.com", "mail.example.com"]`     |
 
 > [!NOTE]
+> When `DEFAULT_DOMAINS` is unset or configured as an empty array, it falls back to `DOMAINS`.
+>
 > `RANDOM_SUBDOMAIN_DOMAINS` only controls automatic random subdomain generation during mailbox
 > creation. It does not create Cloudflare-side subdomain routing for you.
 >
@@ -137,7 +139,7 @@
 
 > [!NOTE] USER_ROLES User Role Configuration
 >
-> - If `domains` is empty, `DEFAULT_DOMAINS` will be used
+> - If `domains` is empty, `DEFAULT_DOMAINS` will be used; if `DEFAULT_DOMAINS` is also empty, it falls back to `DOMAINS`
 > - If prefix is null, the default prefix will be used, if prefix is an empty string, no prefix will be used
 >
 > When deploying through UI, configure `USER_ROLES` in this format: `[{"domains":["awsl.uk","dreamhunter2333.xyz"],"role":"vip","prefix":"vip"},{"domains":["awsl.uk","dreamhunter2333.xyz"],"role":"admin","prefix":""}]`

vitepress-docs/docs/zh/guide/worker-vars.md

@@ -48,6 +48,8 @@
 | `SEND_MAIL_DOMAINS`                   | JSON      | 限制 `SEND_MAIL` binding 可用于哪些发件域名；留空或不配置时允许所有域名                                                            | `["example.com", "mail.example.com"]`     |
 
 > [!NOTE]
+> `DEFAULT_DOMAINS` 未配置或配置为空数组时，会回退使用 `DOMAINS`。
+>
 > `RANDOM_SUBDOMAIN_DOMAINS` 只负责“创建地址时自动补随机子域名”，不会自动帮你创建 Cloudflare
 > 侧的子域名路由。
 >
@@ -131,7 +133,7 @@
 
 > [!NOTE] USER_ROLES 用户角色配置说明
 >
-> - 如果 `domains` 为空将使用 `DEFAULT_DOMAINS`
+> - 如果 `domains` 为空将使用 `DEFAULT_DOMAINS`；如果 `DEFAULT_DOMAINS` 也为空，则继续回退到 `DOMAINS`
 > - 如果 prefix 为 null 将使用默认前缀, 如果 prefix 为空字符串将不使用前缀
 >
 > 通过用户界面部署时 `USER_ROLES` 请配置为此格式 `[{"domains":["awsl.uk","dreamhunter2333.xyz"],"role":"vip","prefix":"vip"},{"domains":["awsl.uk","dreamhunter2333.xyz"],"role":"admin","prefix":""}]`