diff --git a/api/server/middleware/checkDomainAllowed.js b/api/server/middleware/checkDomainAllowed.js
index be3f737ad..914ac44da 100644
--- a/api/server/middleware/checkDomainAllowed.js
+++ b/api/server/middleware/checkDomainAllowed.js
@@ -11,18 +11,25 @@ const { getAppConfig } = require('~/server/services/Config');
  * @param {Object} res - Express response object.
  * @param {Function} next - Next middleware function.
  *
- * @returns {Promise<function|Object>} - Returns a Promise which when resolved calls next middleware if the domain's email is allowed
+ * @returns {Promise<void>} - Calls next middleware if the domain's email is allowed, otherwise redirects to login
  */
-const checkDomainAllowed = async (req, res, next = () => {}) => {
-  const email = req?.user?.email;
-  const appConfig = await getAppConfig({
-    role: req?.user?.role,
-  });
-  if (email && !isEmailDomainAllowed(email, appConfig?.registration?.allowedDomains)) {
-    logger.error(`[Social Login] [Social Login not allowed] [Email: ${email}]`);
-    return res.redirect('/login');
-  } else {
-    return next();
+const checkDomainAllowed = async (req, res, next) => {
+  try {
+    const email = req?.user?.email;
+    const appConfig = await getAppConfig({
+      role: req?.user?.role,
+    });
+
+    if (email && !isEmailDomainAllowed(email, appConfig?.registration?.allowedDomains)) {
+      logger.error(`[Social Login] [Social Login not allowed] [Email: ${email}]`);
+      res.redirect('/login');
+      return;
+    }
+
+    next();
+  } catch (error) {
+    logger.error('[checkDomainAllowed] Error checking domain:', error);
+    res.redirect('/login');
   }
 };
 
diff --git a/api/server/routes/oauth.js b/api/server/routes/oauth.js
index 74faa90ce..0b1252f63 100644
--- a/api/server/routes/oauth.js
+++ b/api/server/routes/oauth.js
@@ -26,9 +26,12 @@ const domains = {
 router.use(logHeaders);
 router.use(loginLimiter);
 
-const oauthHandler = async (req, res) => {
+const oauthHandler = async (req, res, next) => {
   try {
-    await checkDomainAllowed(req, res);
+    if (res.headersSent) {
+      return;
+    }
+
     await checkBan(req, res);
     if (req.banned) {
       return;
@@ -46,6 +49,7 @@ const oauthHandler = async (req, res) => {
     res.redirect(domains.client);
   } catch (err) {
     logger.error('Error in setting authentication tokens:', err);
+    next(err);
   }
 };
 
@@ -79,6 +83,7 @@ router.get(
     scope: ['openid', 'profile', 'email'],
   }),
   setBalanceConfig,
+  checkDomainAllowed,
   oauthHandler,
 );
 
@@ -104,6 +109,7 @@ router.get(
     profileFields: ['id', 'email', 'name'],
   }),
   setBalanceConfig,
+  checkDomainAllowed,
   oauthHandler,
 );
 
@@ -125,6 +131,7 @@ router.get(
     session: false,
   }),
   setBalanceConfig,
+  checkDomainAllowed,
   oauthHandler,
 );
 
@@ -148,6 +155,7 @@ router.get(
     scope: ['user:email', 'read:user'],
   }),
   setBalanceConfig,
+  checkDomainAllowed,
   oauthHandler,
 );
 
@@ -171,6 +179,7 @@ router.get(
     scope: ['identify', 'email'],
   }),
   setBalanceConfig,
+  checkDomainAllowed,
   oauthHandler,
 );
 
@@ -192,6 +201,7 @@ router.post(
     session: false,
   }),
   setBalanceConfig,
+  checkDomainAllowed,
   oauthHandler,
 );
 
diff --git a/api/strategies/ldapStrategy.js b/api/strategies/ldapStrategy.js
index c5796f62e..6f3adf694 100644
--- a/api/strategies/ldapStrategy.js
+++ b/api/strategies/ldapStrategy.js
@@ -4,6 +4,7 @@ const { logger } = require('@librechat/data-schemas');
 const { isEnabled, getBalanceConfig } = require('@librechat/api');
 const { SystemRoles, ErrorTypes } = require('librechat-data-provider');
 const { createUser, findUser, updateUser, countUsers } = require('~/models');
+const { isEmailDomainAllowed } = require('~/server/services/domains');
 const { getAppConfig } = require('~/server/services/Config');
 
 const {
@@ -124,6 +125,15 @@ const ldapLogin = new LdapStrategy(ldapOptions, async (userinfo, done) => {
     if (!user) {
       const isFirstRegisteredUser = (await countUsers()) === 0;
       const role = isFirstRegisteredUser ? SystemRoles.ADMIN : SystemRoles.USER;
+      const appConfig = await getAppConfig({ role });
+
+      if (!isEmailDomainAllowed(mail, appConfig?.registration?.allowedDomains)) {
+        logger.error(
+          `[LDAP Strategy] Registration blocked - email domain not allowed [Email: ${mail}]`,
+        );
+        return done(null, false, { message: 'Email domain not allowed for registration' });
+      }
+
       user = {
         provider: 'ldap',
         ldapId,
@@ -133,7 +143,6 @@ const ldapLogin = new LdapStrategy(ldapOptions, async (userinfo, done) => {
         name: fullName,
         role,
       };
-      const appConfig = await getAppConfig({ role: user?.role });
       const balanceConfig = getBalanceConfig(appConfig);
       const userId = await createUser(user, balanceConfig);
       user._id = userId;
diff --git a/api/strategies/openidStrategy.js b/api/strategies/openidStrategy.js
index 370d502ab..6f35e2af8 100644
--- a/api/strategies/openidStrategy.js
+++ b/api/strategies/openidStrategy.js
@@ -15,6 +15,7 @@ const {
   getBalanceConfig,
 } = require('@librechat/api');
 const { getStrategyFunctions } = require('~/server/services/Files/strategies');
+const { isEmailDomainAllowed } = require('~/server/services/domains');
 const { findUser, createUser, updateUser } = require('~/models');
 const { getAppConfig } = require('~/server/services/Config');
 const getLogStores = require('~/cache/getLogStores');
@@ -400,6 +401,13 @@ async function setupOpenId() {
 
           const appConfig = await getAppConfig();
           if (!user) {
+            if (!isEmailDomainAllowed(userinfo.email, appConfig?.registration?.allowedDomains)) {
+              logger.error(
+                `[OpenID Strategy] Registration blocked - email domain not allowed [Email: ${userinfo.email}]`,
+              );
+              return done(null, false, { message: 'Email domain not allowed for registration' });
+            }
+
             user = {
               provider: 'openid',
               openidId: userinfo.sub,
diff --git a/api/strategies/samlStrategy.js b/api/strategies/samlStrategy.js
index 93118f674..ffc61ad19 100644
--- a/api/strategies/samlStrategy.js
+++ b/api/strategies/samlStrategy.js
@@ -7,6 +7,7 @@ const { ErrorTypes } = require('librechat-data-provider');
 const { hashToken, logger } = require('@librechat/data-schemas');
 const { Strategy: SamlStrategy } = require('@node-saml/passport-saml');
 const { getStrategyFunctions } = require('~/server/services/Files/strategies');
+const { isEmailDomainAllowed } = require('~/server/services/domains');
 const { findUser, createUser, updateUser } = require('~/models');
 const { getAppConfig } = require('~/server/services/Config');
 const paths = require('~/config/paths');
@@ -222,11 +223,19 @@ async function setupSaml() {
 
           const appConfig = await getAppConfig();
           if (!user) {
+            const userEmail = getEmail(profile) || '';
+            if (!isEmailDomainAllowed(userEmail, appConfig?.registration?.allowedDomains)) {
+              logger.error(
+                `[SAML Strategy] Registration blocked - email domain not allowed [Email: ${userEmail}]`,
+              );
+              return done(null, false, { message: 'Email domain not allowed for registration' });
+            }
+
             user = {
               provider: 'saml',
               samlId: profile.nameID,
               username,
-              email: getEmail(profile) || '',
+              email: userEmail,
               emailVerified: true,
               name: fullName,
             };
diff --git a/api/strategies/socialLogin.js b/api/strategies/socialLogin.js
index 5808cbc9b..902c9e873 100644
--- a/api/strategies/socialLogin.js
+++ b/api/strategies/socialLogin.js
@@ -2,6 +2,7 @@ const { isEnabled } = require('@librechat/api');
 const { logger } = require('@librechat/data-schemas');
 const { ErrorTypes } = require('librechat-data-provider');
 const { createSocialUser, handleExistingUser } = require('./process');
+const { isEmailDomainAllowed } = require('~/server/services/domains');
 const { getAppConfig } = require('~/server/services/Config');
 const { findUser } = require('~/models');
 
@@ -17,6 +18,16 @@ const socialLogin =
       const existingUser = await findUser({ email: email.trim() });
       const ALLOW_SOCIAL_REGISTRATION = isEnabled(process.env.ALLOW_SOCIAL_REGISTRATION);
 
+      if (!existingUser && !isEmailDomainAllowed(email, appConfig?.registration?.allowedDomains)) {
+        logger.error(
+          `[${provider}Login] Registration blocked - email domain not allowed [Email: ${email}]`,
+        );
+        const error = new Error(ErrorTypes.AUTH_FAILED);
+        error.code = ErrorTypes.AUTH_FAILED;
+        error.message = 'Email domain not allowed for registration';
+        return cb(error);
+      }
+
       if (existingUser?.provider === provider) {
         await handleExistingUser(existingUser, avatarUrl, appConfig);
         return cb(null, existingUser);