diff --git a/imap_filter/imap_filter.py b/imap_filter/imap_filter.py
index 59f0ec0..69212cc 100644
--- a/imap_filter/imap_filter.py
+++ b/imap_filter/imap_filter.py
@@ -85,6 +85,7 @@ class ImapFilter:
     def _process_filters(self):
         matches = 0
         for mailbox in self.config['mailboxes']:
+            missing_required = False
             for field in REQUIRED_MAILBOX_FIELDS:
                 if field not in mailbox:
                     self._log.warning(
@@ -92,7 +93,10 @@ class ImapFilter:
                         field,
                         mailbox.keys()
                     )
+                    missing_required = True
                     break
+            if missing_required:
+                break
             self.connect_imap(
                 imap_server=mailbox['imap_server'],
                 imap_port=mailbox['imap_port'],