diff --git a/docs/en/install/README.md b/docs/en/install/README.md
index 50c88d74f..c3eab9f5c 100644
--- a/docs/en/install/README.md
+++ b/docs/en/install/README.md
@@ -342,7 +342,7 @@ When adding feeds using RSS readers with HTTP Basic Authentication support, auth
 
 -   `mail`:
 
-    -   `EMAIL_CONFIG_{email}`: Mail setting, replace `{email}` with email account, like `EMAIL_CONFIG_xxx@qq.com`. the value format is `password=password&host=server&port=port`, like `password=123456&host=imap.qq.com&port=993`
+    -   `EMAIL_CONFIG_{email}`: Mail setting, replace `{email}` with email account, replace `@` in email account with `.`, like `EMAIL_CONFIG_xxx.qq.com`. the value format is `password=password&host=server&port=port`, like `password=123456&host=imap.qq.com&port=993`
 
 ### Access Control
 
diff --git a/docs/install/README.md b/docs/install/README.md
index 1779ecd7e..b4bfe5471 100644
--- a/docs/install/README.md
+++ b/docs/install/README.md
@@ -412,4 +412,4 @@ RSSHub 支持 `memory` 和 `redis` 两种缓存方式
 
 -   邮箱 邮件列表路由:
 
-    -   `EMAIL_CONFIG_{email}`: 邮箱设置，替换 {email} 为 邮箱账号，例如 `EMAIL_CONFIG_xxx@qq.com`。内容格式为 `password=密码&host=服务器&port=端口`，例如 `password=123456&host=imap.qq.com&port=993`。
+    -   `EMAIL_CONFIG_{email}`: 邮箱设置，替换 {email} 为 邮箱账号，邮件账户的 `@` 替换为 `.`，例如 `EMAIL_CONFIG_xxx.qq.com`。内容格式为 `password=密码&host=服务器&port=端口`，例如 `password=123456&host=imap.qq.com&port=993`。
diff --git a/docs/other.md b/docs/other.md
index 1be48f602..a003c84b6 100644
--- a/docs/other.md
+++ b/docs/other.md
@@ -1193,7 +1193,7 @@ type 为 all 时，category 参数不支持 cost 和 free
 
 > 仅支持 IMAP 协议
 
-<Route author="kt286" example="/mail/imap/xx@qq.com" path="/mail/imap/:email" :paramsDesc="['邮箱账号']" />
+<Route author="kt286" example="/mail/imap/rss.rsshub.app" path="/mail/imap/:email" :paramsDesc="['邮箱账号']" />
 
 ## 语雀
 
diff --git a/lib/config.js b/lib/config.js
index 499ae98d3..3dfe6c67d 100644
--- a/lib/config.js
+++ b/lib/config.js
@@ -10,7 +10,7 @@ for (const name in envs) {
         const id = name.slice(14);
         twitter_tokens[id] = envs[name];
     } else if (name.startsWith('EMAIL_CONFIG_')) {
-        const id = name.slice(13);
+        const id = name.slice(13).replace('.', '@');
         email_config[id] = envs[name];
     }
 }
diff --git a/lib/routes/mail/imap.js b/lib/routes/mail/imap.js
index f32757996..62a6a545c 100644
--- a/lib/routes/mail/imap.js
+++ b/lib/routes/mail/imap.js
@@ -19,7 +19,7 @@ module.exports = async (ctx) => {
         throw Error('please config email password, host, port in .env file');
     }
 
-    const imap = new ImapClient(mailConfig.host, mailConfig.port, {
+    const imap = new ImapClient(mailConfig.host, parseInt(mailConfig.port), {
         logLevel: 'error',
         auth: {
             user: mailConfig.username,
@@ -47,7 +47,7 @@ module.exports = async (ctx) => {
             const single = {
                 title: item.envelope.subject,
                 description: description.html || description.textAsHtml,
-                guid: item.envelope['message-id'],
+                guid: item.envelope['message-id'] || item.envelope.date,
                 pubDate: item.envelope.date,
                 author: `${item.envelope.from[0].name}(${item.envelope.from[0].address})`,
             };