I'm -1 on this patch as-is. It changes the default error handling behavior from 'strict' to 'replace', for this method. This is a choice that the caller of these methods should make, so I think the default value for the error handling should be 'strict'. If then it is meaningful in mailman to set this to 'replace', this is mailman's choice. Python should never, on its own, create moji-bake.

If you revise this patch, please provide the test case as a patch to Lib/email/test somehow (probably patching both test_email and test_email_renamed).