fix exception

iarchiver/mail.py

@@ -44,7 +44,7 @@ class MailConnection:
         self.mail.login(username, password)
         self.attachments_dir = attachments_dir.expanduser().absolute().resolve()
         self.folder_structure = {}
-        self.logger = logging.getLogger('iarchiver.mail')
+        self.logger = logging.getLogger('iarchiver.mail_conn')
         self.logger.setLevel(logging.INFO)
 
     def load_folders(self):
@@ -77,10 +77,21 @@ class MailConnection:
         date = parsedate_to_datetime(date_header)
         unix_timestamp = int(time.mktime(date.timetuple()))
 
-        from_header = ', '.join(extract_emails(email_message['From']))
-        to_header = ', '.join(extract_emails(email_message['To']))
+        from_addr = email_message['From']
+        to_addr = email_message['To']
+        if not from_addr and not to_addr:
+            return
+        if not from_addr:
+            from_addr = ''
+        if not to_addr:
+            to_addr = ''
+
+        from_header = ', '.join(extract_emails(from_addr))
+        to_header = ', '.join(extract_emails(to_addr))
+        if '@' not in from_header:
+            from_header = from_addr
         if '@' not in to_header:
-            to_header = email_message['To']
+            to_header = to_addr
 
         subject_header = email_message['Subject']
         if subject_header: