I am using smtplib sendmail and \n (line feed) is being added where there was just \r (carriage return).  
This corrupts the file for use with the UNIX tnef utility.  How can I keep the line feed from being added?
Thanks
Email servers are free to change line endings IIRC. They could be various platforms.
If you are transmitting an attachment, use a suitable encoding such as Base64.
Python's smtplib sendmail is inserting line feed