For python exception message capturing you are required to define which type of exception you want to catch. So to do so you will write except Exception, e: instead of except, e that you have written.
So below is the correct way of writing the try/except code which you should write in your code as well to capture the exception message.
Another important advice if you are using Python 3.x then instead of except Exception e you are advised to use except Exception as e.
with open(filepath,'rb') as f:
con.storbinary('STOR '+ filepath, f)
logger.info('File successfully uploaded to '+ FTPADDR)
except Exception, e:
logger.error('Failed to upload to ftp: '+ str(e))