diff --git a/mayan/apps/sources/models/email_sources.py b/mayan/apps/sources/models/email_sources.py
index a681c7f721..57435e201e 100644
--- a/mayan/apps/sources/models/email_sources.py
+++ b/mayan/apps/sources/models/email_sources.py
@@ -284,8 +284,8 @@ class POP3Email(EmailBaseModel):
             )
 
         mailbox.getwelcome()
-        mailbox.user(username=self.username)
-        mailbox.pass_(password=self.password)
+        mailbox.user(self.username)
+        mailbox.pass_(self.password)
         messages_info = mailbox.list()
 
         logger.debug(msg='messages_info:')
diff --git a/mayan/apps/sources/tests/test_models.py b/mayan/apps/sources/tests/test_models.py
index 16a6282118..ab5faa913c 100644
--- a/mayan/apps/sources/tests/test_models.py
+++ b/mayan/apps/sources/tests/test_models.py
@@ -203,7 +203,10 @@ class POP3SourceTestCase(GenericDocumentTestCase):
         def list(self, which=None):
             return (None, ['1 test'])
 
-        def pass_(self, password):
+        def user(self, user):
+            return
+
+        def pass_(self, pswd):
             return
 
         def quit(self):
@@ -214,9 +217,6 @@ class POP3SourceTestCase(GenericDocumentTestCase):
                 1, [TEST_EMAIL_BASE64_FILENAME]
             )
 
-        def user(self, username):
-            return
-
     @mock.patch('poplib.POP3_SSL', autospec=True)
     def test_download_document(self, mock_poplib):
         mock_poplib.return_value = POP3SourceTestCase.MockMailbox()