2 files changed, 4 insertions, 0 deletions
diff --git a/CHANGELOG b/CHANGELOG
index 643a4e6..e5d2fe7 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -4,6 +4,8 @@ Version 0.4.2   - ???
     with the new option '--date'.
   * Fixed a bug where archivemail would complain about messages older than 
     1970. Yes, someone had a 'Date' header with 1967 :)
+  * Complain if the mailbox to be read does not look like a valid mbox-format
+    mailbox.
 
 Version 0.4.1   - 21 April 2002
   * Don't archive messages that are flagged important unless we are given the
diff --git a/archivemail.py b/archivemail.py
index 6cdbdcd..8ac2836 100755
--- a/archivemail.py
+++ b/archivemail.py
@@ -924,6 +924,8 @@ def _archive_mbox(mailbox_name, final_archive_name):
     original.procmail_lock()
     original.exclusive_lock()
     msg = original.next()
+    if not msg and (original.starting_size > 0):
+        user_error("'%s' is not a valid mbox-format mailbox" % mailbox_name)
     while (msg):
         stats.another_message()
         vprint("processing message '%s'" % msg.get('Message-ID'))