[email] header clarification

[Clive Haworth]

I need some clarification on what is and isn't done to mail headers by 
commons email, both setting and getting.

RFC 822 forces all email headers to use characters in the US-ASCII range 
1 through 127. Headers not natively in US-ASCII need to be encoded using 
RFC 2047.

Additionally RFC 822 forces header lines longer than 998 characters to 
be folded.

Does commons email handle all this automatically in ALL cases, some 
cases (and if so which) or not at all?

Regards,
Clive Haworth