> However, there should be a test for that, and I'm curious to know what happens if you use such an address in an address field in the unmodified email package.

I added a test to check if the exceptions get thrown when a address is invalid.

I also added a small test to check how a resulting message should look, it looks good to me but I am not a specialist with email.  Do you have any other ideas how to check if it does not have a negative impact to other parts of the module?


> Instead of directly calling bencode, you should use the charset module and its header_encode method.  Note that you need to turn the charset into a Charset instance first.  The advantage of doing this is that it will choose the "best" encoding to use based on the charset and the contents of the string.

The code also uses email.charset.Charset now.