I've also got a slightly similar error with Guardian:
Code:
Python function terminated unexpectedly: Connection unexpectedly closed
Traceback (most recent call last):
File "/Applications/calibre.app/Contents/Resources/Python/lib/python2.6/site.py", line 147, in main
return run_entry_point()
File "/Applications/calibre.app/Contents/Resources/Python/lib/python2.6/site.py", line 116, in run_entry_point
return getattr(pmod, func)()
File "site-packages/calibre/utils/smtp.py", line 220, in main
File "site-packages/calibre/utils/smtp.py", line 100, in sendmail
File "lib/python2.6/smtplib.py", line 712, in sendmail
File "lib/python2.6/smtplib.py", line 438, in rset
File "lib/python2.6/smtplib.py", line 363, in docmd
File "lib/python2.6/smtplib.py", line 340, in getreply
smtplib.SMTPServerDisconnected: Connection unexpectedly closed
I'm using GMail and sending files to the Kindle through Calibre command line mail program.
What I did find out is that if you close any other email program then it won't fail. I hadn't made a thorough research but it kind of make sense. The chances that an email program hit at the same time that Calibre are proportional to the file size. If you want to try this, then make sure that you close any other email program including those that checks your inbox.