diff --git a/src/calibre/gui2/email.py b/src/calibre/gui2/email.py
index f6a4dd74dc..8e4ce3b4a4 100644
--- a/src/calibre/gui2/email.py
+++ b/src/calibre/gui2/email.py
@@ -126,7 +126,8 @@ class Emailer(Thread): # {{{
             try:
                 job.email_sent_callback(job)
             except:
-                pass
+                import traceback
+                traceback.print_exc()
 
     def send_mails(self, jobnames, callback, attachments, to_s, subjects,
                   texts, attachment_names):