diff --git a/kallithea/controllers/api/api.py b/kallithea/controllers/api/api.py
--- a/kallithea/controllers/api/api.py
+++ b/kallithea/controllers/api/api.py
@@ -674,7 +674,7 @@ class ApiController(JSONRPCController):
         if User.get_by_username(username):
             raise JSONRPCError("user `%s` already exist" % (username,))
 
-        if User.get_by_email(email, case_insensitive=True):
+        if User.get_by_email(email):
             raise JSONRPCError("email `%s` already exist" % (email,))
 
         if Optional.extract(extern_name):
diff --git a/kallithea/lib/helpers.py b/kallithea/lib/helpers.py
--- a/kallithea/lib/helpers.py
+++ b/kallithea/lib/helpers.py
@@ -480,7 +480,7 @@ def is_hg(repository):
 def user_or_none(author):
     email = author_email(author)
     if email:
-        user = User.get_by_email(email, case_insensitive=True, cache=True)
+        user = User.get_by_email(email, cache=True)
         if user is not None:
             return user
     return None
diff --git a/kallithea/model/db.py b/kallithea/model/db.py
--- a/kallithea/model/db.py
+++ b/kallithea/model/db.py
@@ -591,11 +591,8 @@ class User(Base, BaseModel):
         return res
 
     @classmethod
-    def get_by_email(cls, email, case_insensitive=False, cache=False):
-        if case_insensitive:
-            q = cls.query().filter(cls.email.ilike(email))
-        else:
-            q = cls.query().filter(cls.email == email)
+    def get_by_email(cls, email, cache=False):
+        q = cls.query().filter(cls.email.ilike(email))
 
         if cache:
             q = q.options(FromCache("sql_cache_short",
@@ -605,10 +602,7 @@ class User(Base, BaseModel):
         if ret is None:
             q = UserEmailMap.query()
             # try fetching in alternate email map
-            if case_insensitive:
-                q = q.filter(UserEmailMap.email.ilike(email))
-            else:
-                q = q.filter(UserEmailMap.email == email)
+            q = q.filter(UserEmailMap.email.ilike(email))
             q = q.options(joinedload(UserEmailMap.user))
             if cache:
                 q = q.options(FromCache("sql_cache_short",
@@ -628,7 +622,7 @@ class User(Base, BaseModel):
         # Valid email in the attribute passed, see if they're in the system
         _email = email(author)
         if _email:
-            user = cls.get_by_email(_email, case_insensitive=True)
+            user = cls.get_by_email(_email)
             if user is not None:
                 return user
         # Maybe we can match by username?
diff --git a/kallithea/model/validators.py b/kallithea/model/validators.py
--- a/kallithea/model/validators.py
+++ b/kallithea/model/validators.py
@@ -719,7 +719,7 @@ def UniqSystemEmail(old_data=None):
 
         def validate_python(self, value, state):
             if (old_data.get('email') or '').lower() != value:
-                user = User.get_by_email(value, case_insensitive=True)
+                user = User.get_by_email(value)
                 if user is not None:
                     msg = M(self, 'email_taken', state)
                     raise formencode.Invalid(msg, value, state,
@@ -738,7 +738,7 @@ def ValidSystemEmail():
             return value.lower()
 
         def validate_python(self, value, state):
-            user = User.get_by_email(value, case_insensitive=True)
+            user = User.get_by_email(value)
             if user is None:
                 msg = M(self, 'non_existing_email', state, email=value)
                 raise formencode.Invalid(msg, value, state,
diff --git a/kallithea/tests/models/test_users.py b/kallithea/tests/models/test_users.py
--- a/kallithea/tests/models/test_users.py
+++ b/kallithea/tests/models/test_users.py
@@ -72,6 +72,10 @@ class TestUser(BaseTestCase):
         Session().add(m)
         Session().commit()
 
+        u = User.get_by_email(email='MAIN_email@example.com')
+        self.assertEqual(usr.user_id, u.user_id)
+        self.assertEqual(usr.username, u.username)
+
         u = User.get_by_email(email='main_email@example.com')
         self.assertEqual(usr.user_id, u.user_id)
         self.assertEqual(usr.username, u.username)
@@ -82,6 +86,12 @@ class TestUser(BaseTestCase):
         u = User.get_by_email(email='main_email3@example.com')
         self.assertEqual(None, u)
 
+        u = User.get_by_email(email='main_e%ail@example.com')
+        self.assertEqual(None, u)
+        u = User.get_by_email(email='main_emai_@example.com')
+        self.assertEqual(None, u)
+
+
         UserModel().delete(usr.user_id)
         Session().commit()